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An Internet Primer for Economists

ARCHIVED: Last updated January 1996

1. Introduction

In universities and other research institutions more and more computers have been attached to some kind of network in recent years. This local network is often part of the world-wide Internet. Whilst in the 1980's only old-style mainframes and high-end UNIX workstations were connected, by now many personal computers (PCs) have been linked up. Since most offices are equipped with PCs, many users are now able to access a tremendous amount of resources distributed all over the world right from their desk. Starting from literature searches in the local library, the list of possibilities ranges over discussion lists, data archives, to the retrieval of text or graphic files.

This paper gives a short description of the most important tools used on the Internet and surveys the most important resources for economists. It should be regarded as an introduction rather than a complete survey. The rate of technical progress on the Internet is very high, therefore any survey can only be a moment's shot.

Krichel and Wichmann (1994) provide an update to this review

Within the next years we will see many more tools and services appear as well as lots of new resources. We avoid going into too many technical details about the Internet tools or reviewing Internet resources that might be outdated tomorrow. More detailed and up-to-date information on tools and services can always be found in documents named FAQs, an abreviation for "Frequently Asked Questions" on the Internet. The latest FAQs to all subjects are always available by anonymous ftp (see 3.3) from Within the field of economics a periodically updated list of resources is Goffe (1994). A good background paper on the Internet is MacKie-Mason and Varian (1994) who discuss technical as well as economic questions of the network.

The remainder of this survey consists of four sections. In the next section we give a short introduction into structure and development of the Internet. Section 3 describes frequently used network tools, while Section 4 contains a list of Internet resources. Section 5 concludes.

2. The Internet

There is no physical device called "the Internet". The "net" is made up of numerous small network islands in universities, commercial firms and government institutions that are connected by leased high quality telephone lines. While the local area networks (LANs) are owned and operated by the respective universities or other institutions, the connecting networks and services are provided by special institutions, e.g. the NASA or NSFNET in the United States, EUnet in Europe or JANet in the UK. This decentralised nature of the Internet has always been its major feature and is probably one reason for its success.

The Internet began about twenty years ago as a computer network initiated by the US Department of Defense. The ARPAnet, as it was called, was an experimental network. The goal was to find out how to build a computer network such that it would be operational even if a part of it had been destroyed. This task lead to a decentralised network that operates with a packet-switching technique. Every computer (host) on this network communicates with another by sending packets of data to the receiving host, which are unpacked by the recipient. These packets may represent parts of files, electronic mail, or commands; the principle of transmission remains the same. The sending computer divides the data into small pieces, packs them according to a special protocol, called TCP/IP (Transmission Control Protocol/Internet Protocol)and sends them off to the recipient. As with normal postal mail, the sender does not know which way the packet will take, it only knows where the next router is located. This is a machine capable of forwarding Internet traffic to the next router. This router knows to which further router packets, say, to Canada, may be sent. The Canadian router then knows the university, and so on, until some router knows the destination host.

This setup is made possible by assigning a unique address to each computer connected to the Internet, the so-called Internet address or IP-address. It is made up of four numbers between 0 and 255 which are connected by dots, e.g. Since they are often hard to remember, there are also names corresponding to the numbers. The IP-address above could be for a computer called Each component of the name (or the number) is ordered hierarchically according to so-called domains. Thus de (130) is (a part of) Germany, tu-berlin (149) is the Technical University Berlin, ww (200) its department of economics and, finally, xyz (199) the name of a computer in this department. The last part of the name usually denotes the country of the organisation. In the United States the ending shows the kind of institution, so for example edu indicates an educational unit and gov a government agency.

The Internet is growing rapidly. From 1985 to January 1994, it has grown from about 200 to more than 21,000 networks. The number of computers connected to it has in the same period increased from 1000 to now over 2 million. The traffic on the network is currently rising at a speed of about 6% per month.

Numbers are from MacKie-Mason and Varian (1994).

Most readers in the United Kingdom will have come accross the term "JANet" which stands for Joint Academic Network. JANet was first introduced in the mid 80s as a closed network for the UK only. It operated via X.25 lines on a sequence of protocols called the "coloured book" protocols. One of the most noticable differences was that the host names where instead to, as you would expect within a TCP/IP framework. As the importance of TCP/IP in the rest of the world continued to grow, so did the inconvenience caused by the use of a different protocol. In 1991, the JANet/Internet protocol system (JIPS) was introduced. This software allowed the use of the TCP/IP protocol on the X.25 lines. Three years later, a second phase of JANet called SuperJANet was introduced. This second phase is entirely TCP/IP based. JIPS and SuperJANet users are de facto on the Internet.

Because of the decentralised nature of the Internet, it is rather easy to connect an individual machine to it, if the institution is already connected to the Internet. All that is needed is an Ethernet-card (a piece of hardware to handle the network communication), a connection to the local area network, and an IP-address, which can usually be obtained from the local computing centre. Do not pick your own without advice. As the last step some software has to be installed that allows to access the Internet resources. We will review this software in the next section.

3. Internet Tools

In this section we survey the most important applications and tools for Internet communication. From the large variety of Internet tools we have selected those that matter most for the academic practitioner. More tools are described by Kehoe (1992), Kroll (1994), LaQuey and Ryer (1993) as well as Gaffin and Heidkoetter (1993). We focus on, respectively, electronic mail (e-mail), terminal emulation on remote computers (telnet), file transfer over the Internet (ftp), tools to access distributed information (gopher, WWW), and network news. At the end of each section we give a short list of public domain software that implements the tool. This software is free and can be obtained by anonymous ftp (see 3.3) from the indicated source. Note that these lists of software packages are not exhaustive.

3.1. Electronic Mail

Electronic mail (e-mail) is probably the best known form of Internet communication. Nowadays, not only plain texts can be transported via e-mail but almost anything: files, graphics, and even sound. However, there is so far no universally accepted standard for encoding non-text e-mail. Therefore mailing non-text items requires agreement between sender and recipient about the encoding tool. Since almost every mailing software uses its own encoding method, this kind of communication remains restricted to users of the same software. There exists a proposed standard for mailing non-text items, which seems to be gaining larger acceptance. This protocol is called MIME (Multipurpose Internet Mail Extensions). But the main use of e-mail is still for plain text.

Almost all Unix computers have a mail programme already installed which is usually called "mail". For PC-users things are slightly more complicated because the PC operating system is generally unable to receive mail whilst running another application. Apart from installing the mail software on the PC, the mail user must obtain a user account on a dedicated mail server, usually a Unix machine or a Novell server. Mail for the PC user is received by this mail server and forwarded to the PC upon request. Most departments or computing centres have already set up dedicated machines for this task so that the PC user only needs to install a suitable mail client software. The two most used mail programmes for the PC are Pegasus Mail in conjunction with a Novell network and Popmail if the mail server is a Unix machine. Using the mail software is fairly straightforward. We therefore focus on the e-mail message itself and its components.

An e-mail message consists basically of two parts: the "body", which is the actual text, and some technical information in the "header" of the message. The header contains a series of fields, some them are shown in the mailing software and at least one, the recipient's address, has to be filled in when sending mail. The address always goes into a field labelled " To:". Similarly, there exists a " From:" field which is filled in automatically and identifies the mail sender. The subject can be put in a field called " Subject:". Finally a " Cc:" often appears. This stands for carbon copy and filling it in will send a copy of the mail to the stated e-mail address.

There are a number of optional lines that can be included in the header. The Reply-To: line, for example, can be used to direct replies towards a specific address. For example, when mailing out the communist manifesto, you might enter the line Reply-To: Karl Marx <> in the header to redirect responses towards the author. On arrival, the header will also contain a list that records all systems through which the message has passed.

The most important part of the header is the recipient's e-mail address. If a message does not reach the recipient, this is usually due to a mistake in the address field. This can easily happen because e-mail addresses are often somewhat cryptic, which leads to frequent typing mistakes.

Generally an Internet e-mail address consists of two parts: a user name (the login name on the mail server) and the mail server's IP address. Both are separated by the (@) sign, e.g. This address may be used to send mail to the President of the United States. Here president is the user name and is the computer's IP address. If the recipient is not connected to the Internet but to another network like BITNET or EARN usually the name of this network is added to the e-mail address. A person reporting her BITNET address as SP0815@DHHUNI99 can be reached from the Internet by mailing to SP0815@DHHUNI99.bitnet. The mail will then be sent to the next gateway between the networks. CompuServe users can also be reached via Internet e-mail. Here an additional modification is necessary: a CompuServe username consists of two numbers separated by a colon. The colon must be replaced by a period and an ending has to be added. Thus, the user 0815,000 has the e-mail address For further details of Internet mailing and trouble shooting see Kroll (1993).

When an e-mail is returned to the sender, the returned mail contains a line that indicates the problem. Examples are: ... 550 User unknown, ... SMTP Service unavailable on destination host, or ... 550 Host unknown (Authoritative answer from name server). In a majority of cases, the problem is caused by a typing mistake. Otherwise, the address may be wrong or the owner may have changed her address. A real network problem is rare.

There are many features built into the mail software to facilitate e-mail, especially if you send and receive a lot. To name but a few, aliases (abbreviations) can be defined for e-mail addresses, mailing lists can be set up or signature files including personal information can be defined. Some e-mail programs can even filter incoming mail or blow a whistle upon receipt of mail.

Here is a list of public domain software for e-mail:

Software...... anonymous ftp-server... Directory
POP server.... /pub/pop/popper
POPmail....... /pub/POPmail
NUPop......... /pub/nupop
Pegasus Mail.. /pub/pegasus

3.2. Telnet

Telnet is an Internet communication protocol that regulates the interactive use of remote computers. Usually the Unix or PC software have the same name for this purpose. By using this software the PC behaves like a terminal of the remote host. The only difference with a "real" terminal is that both are not hard-wired but rather use the Internet to communicate. Therefore it basically makes no difference if the remote host is in the same room or on the opposite side of the planet.

While Unix machines are usually shipped with a telnet software, this is not the case for PCs. However, telnet is part of most commercial TCP/IP (the Internet network protocol) based network software like Sun's PC-NFS or FTP's PC/TCP. There is also a wide range of public domain software for DOS, Windows or Macintosh available (see below).

The use of these programmes is very similar as far as the telnet session itself is concerned. Telnet is usually started with the remote host's IP address, which might be given in name as well as in number form. A connection is established as soon as the remote host asks for a login name. If the connection is not established the program often changes into command mode which can be left by typing quit. A simple session may look as follows (user commands are underlined).

C:> telnet
Connected to rollmops.ww.TU-Berlin.DE.
Escape character is ^]

NeXT Mach (rollmops) (ttyp0)

Last login: Mon Sep  6 03:40:31 from
rollmops> exit
Connection closed by foreign host.
For security reasons the password is not echoed on the local screen.

Usually, a user account with password on the remote host is necessary to use the remote computer. An exception are most library OPACs (Online Public Access Catalogues) and other publicly accessible databases or special programmes. The major list of OPACs is compiled by Barron and Mahe (1993). It contains a short description of how to access the mentioned libraries and some information about the different types of OPAC.

A special case, which occurs frequently when connecting to US libraries, are IBM mainframes that require emulation of an IBM3270 terminal, while telnet usually behaves like an ancient VT100 terminal. (Most hosts know how to handle this type of terminal and so does the telnet software.) While this is seldom a problem on Unix machines, some types of terminal software for PCs can not emulate an IBM3270 terminal. Those that can often have a separate programme called tn3270 which is started like telnet. Whether an OPAC requires a 3270 terminal can be checked on OPAC lists or found out by trial and error. If the connection is closed silently, this might be the reason.

Sometimes an Internet resource indication not only contains the remote host's IP address but also a number. In this case the number is a non-standard port number. These numbers allow a machine to distinguish between different communication streams. With a non-standard port number some special application is often launched directly without the need to give a login name. You would use telnet with the portnumber like telnet host.with.strange.port 999.

Public Domain Software for telnet can be obtained from:

Software ____________ anonymous ftp-server _______ Directory

NCSA Telnet ............ .......... /pub/Telnet
NCSA Telnet for Windows............ .......... /pub/Telnet
WS_FTP ............ .......... /pub/msdos

3.3. Ftp

Ftp stands for "file transfer protocol" and as for telnet is also the name of the software. Using ftp, files may be copied from remote to local computers or the other way round. It might seem confusing at first that telnet may not be used for this purpose, and that an extra software is needed for file transfer. This goes back to the old days of computing when files were stored in the mainframe and the terminal's only task was to tell the computer what to do. Only in modern PCs, terminal and file storage are combined in one machine.

To connect to a remote host for ftp, a user account with password on the remote computer is usually necessary. A notable exception are the so-called "anonymous" ftp-servers. These are machines that offer all kinds of data for retrieval by anybody.

For the usage of ftp it is useful to be aware of the following commands:

ascii ......... ascii mode to transfer plain text (default)
binary ........ binary mode to transfer programs or compressed data
cd ............ change directory on remote host
lcd ........... change directory on local host
dir ........... show directory contents on remote host
get ........... copy one file from remote to local computer
mget .......... copy several files from remote to local computer
put ........... copy one file from local to remote computer
mput .......... copy several files from local to remote computer
pwd ........... print working directory on remote host
help .......... help
quit .......... quit

The program is started on the command line with ftp the.ip.address. To connect to an anonymous ftp-server you should give the login ftp or anonymous. The convention is to enter your e-mail address as password. Like in telnet it is not echoed on the screen. A short session might look as follows:


C:> ftp
Connected to
220 nber FTP Server (SunOS 4.1) ready.
Name ( ftp
331 Guest login ok, send ident as Password.
230 Guest login ok, access restrictions apply.
ftp> cd pub/nber
250 CWD command successful.
ftp> dir
200 PORT command successful.
150 ASCII data connection for /bin/ls (0 bytes).
total 1332
-rw-r--r-x  1 2158     wheel     1189424 Jan  7  1992 pwt5.asc
-rw-r--r-x  1 2158     wheel        9066 Sep 28  1992 pwt5.doc
-rw-r--r-x  1 2158     wheel        3005 Jan  7  1992 pwt5a1.doc
-rw-r--r-x  1 2158     wheel       11834 Jan  7  1992 pwt5a2.doc
-rw-r--r-x  1 2158     wheel       67455 Jan  7  1992 pwt5b2.doc
-rw-r--r-x  1 2158     wheel       67455 Jan  7  1992 pwtb2.doc
226 ASCII Transfer complete.
403 bytes received in 0.79 seconds (0.5 Kbytes/s)
ftp> ascii
200 Type set to A.
ftp> get pwt5.doc
200 PORT command successful.
150 ASCII data connection for pwt5.doc (9066 bytes).
226 ASCII Transfer complete.
local: pwt5.doc remote: pwt5.doc
9350 bytes received in 68.37 seconds (0.13 Kbytes/s) ftp> quit 221 Goodbye. C:> ----------------------------------------------------------
The first string (here: -rw-r--r-x) in a row denotes the access rights as well as the type of each item. If the first letter is a d the file is a directory while a - denotes a plain file. The last three letters denote the rights of the anonymous ftp-user; r stands for readable, w for writeable and x for executable. To access directories, they must be executable. Files available for the public are usually stored in a directory called pub and in its subdirectories. Note that in Unix directory names are sepatated by " /" and not by "\backslash" as in DOS.

Large files on ftp archives are often compressed (packed) to save disk space and transfer time. Packing can be detected from the filename ending. A file named is compressed with the DOS programme PKZIP, while large.whale.Z is packed with the Unix command "compress". Other common endings for compressed data are gz, z, zoo, sit, or lzh. Public domain software to decompress files is usually available from the local computing centre. Some newer ftp servers also offer the option to send compressed files in uncompressed form. You simply have to enter the file name without the compression ending, get the file large.whale.Z decompressed, simply enter get large.whale.

Public domain software for ftp is usually shipped together with the telnet software. If you do not have ftp access, you may want to check into these FTP-by-Email services

This list is part of Scott Yanoff's Internet services list; to obtain a copy send a mail with no subject to

Hostname_____________________ Body ____________________Area help (return) quit US help Europe help or ftplist BITFTP@DEARN help or ftplist Europe

3.4. Gopher

Gopher is a more recent development in Internet communication. Gopher was designed at the University of Minnesota as a campus wide information system with the aim that each department should be able to collect and organise their own information on their own computers without the need for a central coordinator. In addition any user should be able to access this information, e.g.electronic phone books, library catalogues or announcements of cheese \& wine parties, from any computer without specialist technical knowledge and no knowledge of where the information is physically stored. The developers achieved this goal by using the Internet protocols and by including tools like telnet or ftp in gopher. The central idea is the so-called client-server architecture, using server software that runs on the computer storing the data and a client software on the user's machine. The client software allows the user to communicate with gopher servers. For an exhaustive treatment of gopher see Lindner (1993). After about three years the system is now spread over the whole Internet and there exist thousands of gopher servers worldwide.

For the user, gopher is organised like a menu or a directory tree. When making your way through a series of directories to search for a piece of information, you might have connected to several gopher servers all over the world without even noticing it, because the gopher client will connect from one server to the next. A server is in most cases set up by university departments or research institutions who install the server software and update the information it contains. They also set up a directory structure suitable for the gopher's main topic. The information is stored within these directories. It can be text or binary files, graphics or sounds. Links to other gopher servers are included, as well as telnet or ftp sessions and index searches.

While the gopher server administrator has to spend some time on structuring the information in a reasonable way, all the user needs to to is to install a gopher client on her machine. Clients are by now available for most operating systems.

Suppose you are interested in the Summers/Heston (1991) dataset also called the "Penn World Table", which contains macroeconomic data for a large variety of countries on a purchasing power basis. A link to this dataset is included in the directory structure of a gopher server in Berlin. To call this server type gopher otto.ww.TU-Berlin.DE. [UPDATE: This server is no longer active. This article is kept for historical purposes only.]

Upon connection, you will get the following screen:

      Internet Gopher Information Client 2.0 pl5

       Root gopher Server: otto.ww.TU-Berlin.DE
      1.  ---------------------------------------.
      2.   Gopher Server Economics.
      3.   Technical University Berlin.
      4.  ---------------------------------------.
      5.  About this gopher.
      6.  New! Improved! Life! Gopherchanges.
      7.  Dept. of Economics - TU Berlin/
 -->  8.  Economics/
      9.  Mathematics/
      10. Politics/
      11. Services/
      12. More Gophers, Gateways and other nifty stuff/
Press ? for Help, q to Quit, u to go up a menu         Page: 1/1
This is the gopher server's root directory. A dot at the end of a line denotes a text file while a slash indicates a directory. Using the arrow keys you move the cursor to the line which is likely to contain the required information. Hit "return" to enter the Economics directory. By changing directories a few times you will finally get to the wanted data. Further use of the "return" key would bring the contents of the ReadMe file on the screen.

       Internet Gopher Information Client 2.0 pl5 

              Penn-World Table 5.5 (USA)

 -->  1.  Penn World Tables: ReadMe.
      2.  Penn World Tables: Description.
      3.  Penn World Tables: Data.
      4.  Penn World Tables: Compressed Data.
Press ? for Help, q to Quit, u to go up a menu         Page: 1/1
Its ease of use and its ability to combine both local and remote information explain the popularity of gopher. It has spread beyond the university sector to organisations such as the NBER, the United Nations and the World Bank.

A complete collection of gopher clients and server software can be found at
This syntax is explained in the next section.

Internet users who do not have a gopher client at their disposal may use public telnet accounts with gopher clients. Telnet to one of the following sites and you will find yourself in a gopher menu.

Hostname ________ IP Address ______ Login _____ Area      gopher      North America    panda       North America         gopher      North America      gopher      Europe     gopher      Sweden     info        Australia      gopher      South America         gopher      Ecuador      gopher      Japan

If you do not even have a telnet facility you might wish to use gopher by mail. Use the sites in the following table:

Hostname __________________ Subject ____ Body help help ..................... help

3.5 World Wide Web

Similarly to gopher, World Wide Web (WWW) is a tool to access distributed information in the Internet. The WWW project has been started by CERN (the European Laboratory for Particle Physics) and is based on hypertext and hypermedia. Hypertext is text with links to other texts---like footnotes in scientific papers---that are called up by a simple mouse-click. If the new document is hypertext again, it also has references in it that can be followed. Hypertext is a subset of hypermedia, which can also contain other kinds of media, e.g.sound, graphics or even animations.

To access "the web", you need a browser programme similar to the gopher client. Such programmes are now available for most computer systems. The browser reads hypertext documents by following the links in the document. They can run telnet session or use ftp and gopher servers. World Wide Web can therefore be considered to be the most inclusive Internet tool. For graphical interface systems like MS-Windows or X-Windows, NeXTStep and Macintosh, there are graphical browers that can not only access character based information, but also links to graphics and sound. These browers have become very popular.

In the field of economics there are still very few hypertext servers, and certainly far less than gopher servers. One of these is located at the CTI Centre Centre for Economics (see section 4.2.3.). Using the NCSA Mosaic browser the root page of this server looks as in Figure 1. Clicking on the underlined "CTI subject centres" would get to similiar servers related to other discplines.

Figure 1

For those who want to try out the World Wide Web without installing a browser, some telnet accounts with plain text browsers have been set up. To start, simply telnet to one of these machines.

Hostname                  Login           Country                -             Switzerland       www            USA               www            USA             www            Israel              www            Finland

Compared to WWW, gopher is still in wider use. One reason is that hypermedia documents with lots of text and graphics included are relatively large and need a longer time for transmission if the Internet is relatively crowded. Within the United States with relatively good Internet connections and the Information Highway about to come, hypertext documents are becoming more and more fashionable. In Europe and other parts of the world where the Internet is made up of dusty land roads rather than super highways, gopher will probably remain more popular for a while.

Public domain WWW browsers may be obtained from:

Software               anonymous ftp-server     Directory

DosLynx              /pub/WWW/DosLynx
Mosaic for Mac        /Mac/Mosaic
OmniWeb for NeXTStep        /pub/software
Mosaic for Windows        /PC/Mosaic

One of the most important effects of the spread of WWW has been the increased use of the URL. URL stands for Uniform Resource Locator. It is a convention initially adopted by the web to name the place where a resource can be found. The URL tells the client software where to find a resource and how to access it. A URL consists essentially of two `parts, the name of an access protocol and a string that this protocol can resolve to obtain the exact location of the resource. In section 4, we will list URL information for the resources. Here we will give a simplified account of the URL syntax; see Berners-Lee (1994) for further details.

For mail, the URL takes the form mailto::user@hostname For ftp, the URL is written as ftp://host/path, where host is the Internet host, and path is the path of the resource. Telnet sessions are represented as telnet://login where login stands for the combination accountname:password@host, when we omit the password none is required. Gopher sessions are represented as gopher://host:port/type/path where type is an indication of the type of gopher object. Finally when refering to WWW's own hypertext transfer protocol, we represent the location as http://path.

3.6.Network News

Network news is the Internet bulletin board. It is organised in so-called newsgroups, each dealing with a special topic. When a user posts news to a group it is mailed to all sites that receive this group. A typical news server carries between 2000 and 4000 newsgroups and can receive as much as 50 Megabytes of news per day. Like many other Internet applications it is based on a client-server model. The client software---called news reader---connects to a news server to retrieve certain articles on that bulletin board. Most institutions have their own news server to minimise off-site Internet traffic. This server is fed by different sources: Usenet, a set of newsgroups generally considered to be of interest globally, local newsgroups that contain information only for interest to a country, city, network or institution, and finally commercial newsgroups. These newsgroups are organised much like IP adresses in groups, subgroups, etc. For example the Usenet news group sci.econ is a subgroup of the group sci. Unlike some other applications reviewed here, network news is not confined to the Internet.

Most news readers run on Unix machines (e.g., rn, nn, trn, tin), but there are also some available for Macintosh or Windows. Once the software is set up, you can read news articles, reply to the original poster via e-mail, post a follow-up article, post your own questions or comments to ongoing discussions, or---and this a very important feature---filter out postings that contain certain keywords or belong to certain ongoing discussions. Generally, most of the news articles have a low information value, but there are some notable exceptions. These are newsgroups that are concerned with technical information, moderated news groups and some scientific news groups that have a technical or a rather narrow subject.

4.Internet services

There is no good classification of Internet resources. Our approach is partly based on the protocol, (mail, news, gopher\dots), and partly based on the type of information that is offered. We review mailing lists, newsgroups, data archive, literature services, and academic projects. We did not include all resources mentioned in Goffe (1994).

4.1. Mailing lists

The oldest type of service on electronic networks is the maintenance of electronic mailing lists. The general principle of these lists is very simple. When one sends a message to a list, the message is forwarded to everybody on that list. In detail, arrangements may vary. Some lists are "closed", may only subscribe when admitted by the "listowner", but most lists are open. Some lists distribute any message sent to the subscribers immediately, on others messages are first reviewed by a moderator. On some lists, the reply address points to the list, while on a minority of lists replies default to the original poster, and if you wish to send your reply to the list you need to mail a copy. Some list are maintained by humans, and therefore need a human intervention to subscribe or unsubscribe, but most lists have a programme which deals with this type of administration. To obtain more information about a list's subscription procedure mail the single word help---not in the subject header, but in the body of the message---to the subscription address. If the list is managed by a programme, this will return a list of instructions that are valid for the particular software that manages the list. Usually there are many commands that allow you not only to subscribe and unsubscribe, but also to change mailing options, to see a list of subscribers, to obtain back issues of messages, or to query the archives of the list for posts that contain certain keywords. In the following, we have tried to group different lists on similar subjects together.

4.1.1.General Economics lists "List of the Faculty of Economics, University of Amsterdam". This is the largest general purpose economics list in the world, with over 600 subscribers. It is unmoderated, but replies are directed towards the individual poster rather than the list. It carries new entries for NetEc (see section 4.3.2), as well as some general inquiries, often on computing-related problems. Subscribe to, the "CTI Centre for Computing in Economics List" for academic economists. This list is the largest UK based list, opened by the CTI Centre for Economics. Discussions are rare on this list, but it carries job advertisements and other sometimes useful announcements. All UK based academics should subscribe to "Political Economy" This list is no longer a pure list since it now carries the messages sent to the newsgroup sci.econ.research, a moderated newsgroup. Often the list carries genuine discussions in any field of economics. is the distribution list for the "Cyberchronicle of Political Economy" the world's first refereed electronic journal in Economics. The journal will be based on the LaTeX document formatting system and the sole issue of the journal to date contained an review of LaTeX. Future editions should feature brief articles, book reviews and comments. For subscription to the journal mail to, for submissions of articles mail General inquiries about the journal should be sent to

4.1.2 Empirical and Computational Economics "List of the Society of Computational Economics", in the sense that it often mirrors messages on corryfee. Subscribe to "Intelligent Systems for Business and Economics Digest". This is a list that is similar in purpose to csemlist, but it is carried as a digest, i.e. large messages are sent out that bring together a number of contributions. In the past many messages where concerned with applications of neural networks. Subscribe to "Economic Nonlinear Dynamics List". Low traffic list with good quality contributions. Subscribe to on experimental economics. The list carries new entries in the library of the Centre for Experimental Economics at the University of York, England. Subscribe to

4.1.3.Economic History "Economic History E-mail Conference" was the first list for economic history, and it has mainly European, especially British subscribers. This list publishes an Economic History Newsletter that covers a variety of topics. Subscribe to "Teaching and Research in Economic History". This list is sponsored by the Cliometric society, which has also opened a gopher server, see below. It was founded in late 1993 and is moderated.

4.1.4. Teaching Economics and Economics Education on "Research in Economic Education". This is a list that used to be quite active, but has seen fewer messages recently. Your subscription should go to on "Teaching of Economics". This list is more practically oriented towards the teaching of the subject. This list has become fairly active and carries genuine discussions., a discussion on the "Economics and Management of Education". The list is based at It has essentially a UK based membership and has had few contributions.

4.1.5.Law and Economics

There are three lists, the first one of which is the most active: the "Forensic Economics List". Subscribe to "Law and Economics", subscription is handled by "An Economic Analysis of Law". For a subscription write to

4.1.6.Regional Lists concerns "Discussions on the Federal Tax System" of the United States. This list has a fairly high amount of traffic. However subscribers seem to be more interested in exchanging advice on their personal tax situation rather than discussing the properties of the system. Subscribe to called the "Eastern Europe Business Network". This a moderated but still heavy traffic list that is essentially concerned with the needs of business in Eastern Europe. It carries only business information and has no input from researchers interested in the broader issues confronting the Eastern European economies. However, it might be useful to obtain general information about those countries. Subscribe to on the "Transition in Eastern Europe & the former Soviet Union". This is the forum for economists interested in Eastern Europe, but contributions to the list have been scarce. Subscription requests should be mailed to "Discussion of the Czech Republic's Economy". The list, which opened in April 1994, operates in the Czech language. Despite its recent age and linguistic entry barrier it is fairly active. It is related to all aspects of the Czech economy and should be a valuable tool for those who seek information on this economy.

econom-l@brufsc.bitnet intended to "Discussao Sobre Economia Brasileira" where you can subscribe to listserv@brufsc.bitnet. for "Academic Discussion of Research in the Chinese Economy". is the address at which the list owner may be reached.

carecon@yorkvm1.bitnet is a fairly active list on all aspects of the "Caribbean Economy", subscribe to listserv@yorkvm1.bitnet. stands for "Information Bank on African Development Studies". This mailing list is run by the African Technical Department at the World Bank to spread information about development issues in Sub-Saharan Africa. Subscribe to is a more general list on the problems of developing countries. This used to be a very active list. Until mid 1993, it used to carry many messages that discussed the politics of development. Now only a few announcements are sent from time to time. Various attempts to stimulate discussions have failed. Subscribe to

4.1.7.Agriculture, Development and International Issues "International Political Economy" This list is more geared towards political scientists working at the interface with economics. Subscriptions requests should be mailed to "International Trade", another list maintained by, but with much smaller traffic. "Community and Rural Economic Development Interests", a low-traffic list that suffers from not having a closely defined aim. "Land & Resources Economics Electronic Conference", is a more recent then ruraldev, and with less traffic. Subscribe to "Local Economic Development", a topic that is sufficiently vague to attract many comments; subscribe to "Mineral Economics and Management Society" is a very small list, which essentially is as a communication channel for the association's president. Subscribe to

4.1.8.Business and Finance "Risknet" discussions on risk and insurance. The list is closely related to the gopher and WWW servers on these issues (see section 4.3.2). Subscribe to "The Electronic Journal of Finance" This list has a large volume of subscribers, but the number and quality of contributions has remarkably declined since early 1994. Subscribe to The "Electronic Journal of Investing" was created by the owner of the previous list to accomodate for the demands of people interested in financial investment. It now carries postings of stockmarket news. Subscribe to "Reports of Macroeconomics Statistics and Related Discussion". This list appears in this catqegory because it carries the "Daily Summary" by the Small Investor Company, which contains a summary of political development together with an extensive set of daily data on the American markets. To join the list, subscribe to "Business Libraries Discussion List" This is the list for business librarians, and because there is no economics librarian list, it serves this group as well. All the large libraries in the world have somebody on the list. For any economist who is looking for data or some difficult reference problem, this is the list to contact. One might consider subscribing, ask the question and unsubscribe later, to avoid the heavy traffic. Subscribe to

4.1.9.Lists with a Progressive Orientation stands for "Post-Keynesian Thought", a list with fairly heavy traffic for discussion among the followers of the Post-Keynesian paradigm. The list is also associated with a discussions paper archive that can be accessed via gopher and ftp (see section 4.3.2.). Anybody who is interested in Keynesian economics should subscribe to "Ecological Economics", This list is concerned with all economic aspects of the environment and of environmental activism. Subscribe to, is the "Progressive Economists Network" that unites all shades of left-wing economists in a fairly active list. Subscriptions are handled by

4.1.10. Human Resources was opened to discuss "Quantitative Techniques in Health Economics", but it has been silent. Subscribe to "Feminist Economics Discussion List" This fairly active list is concerned with a general discussion on feminist economics and it has a working paper archive that operates via e-mail. "Labor Economics" was initially opened as a student list. It now is an open list for all questions of labour economics, but it is a quiet list. Subscribe to

4.1.11. Internet for Economists Lists "Gophers in Economics" A low traffic list, but indispensable for anybody who is administering a gopher system for Economics. Subscribe to about the SEC Edgar database (see section 4.3.1). This list is restricted to announcement of news regarding this service. about the WUSTL archive for Economics working papers (see section 4.3.2.). Subscribe to

4.2. Usenet Newsgroups

There are not many newsgroups dedicated solely to economics. The first newsgroup concerned with economic questions was sci.econ. This group is not moderated and traditionally carries a lot of political arguments. Therefore the interest of academic economists in the group has always been limited. In 1993 a moderated newsgroup sci.econ.research was established that is restricted to academic economics. The group often carries discussions about course books and data sets as well as conference announcements. It is archived on
Many economists find it rewarding to look into the mathematics and statistics newsgroups. These are generally a good place for technical questions. The newsgroups sci.math.num-analysis, sci.math.research, sci.math.stat, and sci.math.symbolic are not only of interest to mathematicians. Mathematical software programmes (e.g., Mathematica, Maple, Matlab) and their problems are discussed regularly. This is a good occasion to seek for assistance, because questions are often answered by the software manufacturers themselves. The same applies to the statistical newsgroups sci.stat.consult,, and sci.stat.math. Some econometric and mathematical software packages have their own newsgroups. These are, comp.soft-sys.shazam, comp.soft-sys.spss, and comp.soft-sys.matlab.

4.3. Archives

Here we bring together projects that use a variety of software bases. Most of them are centred around a gopher server, but allow for other access modes. We expect that in the near future many projects will be primarily WWW based.

4.3.1. Data Archives

Most of the data archives that are listed here, are based in the United States and therefore have a bias towards providing US statistics. The United Kingdom however is closing the gap in the access to economic datasets through services provided by the Manchester Computing Centre. Here we list some important data sites that should be of interest to a number of economists. We are leaving out some smaller and more specialised datasets to conserve space. Another criterion for selection was that the site had to offer the actual data rather then information about the data.

The Economic Bulletin Board

The full Economic Bulletin Board of the United States can be accessed on the Internet as telnet:// It contains about 2000 files from the Commerce, the Treasury and Labor Departments, the Federal Reserve Boards and other institutions. The areas covered are: Current Business Statistics, Economic Indicators, Employment Statistics, Energy Statistics, Foreign Trade, Eastern Europe Trade Leads, Industry Statistics, International Market Insight Reports, Monetary Statistics, National Income and Product Accounts, Press Communiquees of the US Trade Representatives, Price and Productivity Statistics, Regional Economic Statistics.
This is a very rich resource, but unfortunately it lacks structure. A further complication arises because the format of the data is changing. Some are plain ASCII files, others are self-extracting DOS files, and others are prepared for spreadsheet use. Full access to the system is charged for; mail to obtain current rates. There is a guest facility whereby you can use the system free of charge for 20 minutes, but not all files are available. However, under U.S. law the information that is contained on the EBB is not copyrightable. Therefore once extracted, copies can be made. That allowed the University of Michigan to open a gopher server where the most important part of the EBB's contents is regularly copied to.
Although they download most of the files put up by the Commerce Deptartment, the Michigan version is not a comprehensive archive of the government's EBB files. They do keep some of the historical series (as in the Current Business Statistics area, for instance), but usually they purge or replace files on a monthly, daily, quarterly, or annual basis, depending on how often the Commerce Dept posts new versions. To access the Michigan server, use the URL gopher:// Access via ftp is also possible


This archive is the result of a project to construct an Input/Output model for the United States at the University of Maryland. The data comprises the National Income and Product Accounts, the balance of payments including foreign direct investment, the flow of funds accounts, employment and earnings data, consumer and producer price indexes, as well as business conditions statistics. There is less data than on the Economic Bulletin Board but the organisation of the data is much better. The URL is gopher://


This is a series of public databases released by the United States Bureau of Labor Statistics. It provides current and historical data for 26 surveys, more being added. At the time of writing, there are 7 surveys on prices, 4 on productivity, 2 on bargaining, 11 on various aspects of employment, and there is a copy of the international labour statistics. The organisation of the data is very rigorous. The site also contain a large number of press releases. The extensive documentation of the system can be found in pub/doc. The URL for the system is For help and comment mail

The Luxembourg Income Study (LIS)

is a database of social and economic data from household surveys for over 20 countries covering the period 1968 to 1989. During 1994 and 1995, additional surveys will be added for the early 1990's. It contains more than 240 variables, concerning household and individual income, demographic variables, employment and education. Because some member countries have imposed restrictions its usage, the data can not leave the Luxemburg central site, nor can it be accessed directly. Jobs are submitted via e-mail and outputs are returned automatically. Currently SPSSX is the only analysis package supported. Mail eplisjr@luxcep11.bitnet for initial contact.

Manchester Computing Centre (MCC) National Datasets Service

MCC currently receives funding from HM government to provide a range of datasets services to the UK academic community. These are based on the machine The data include the 1991 UK Census of Population (Local Base and Small Area Statistics, Samples of Anonymised Records, Postcode to ED Directory), the 1981 UK Census of Population (Small Area Statistics), as well as the large national surveys like General Household Survey, the Family Expenditure Survey, the Labour Force Survey, the Farm Business Survey issues and the first wave of the British Household Panel Survey.
More data will be made available later, including the National Child Development Study, the Quarterly Labour Force Survey and more waves of the British Household Panel Survey. The economic timeseries of the UK's Central Statistical Office are also available. Holding of international data is more sketchy. There is data from the International Monetary Fund (IMF) available but unlikely to be updated since the IMF discontinued the distribution of the data tapes via the ISPCR. MIDAS holds the following sets: International Financial Statistics, Direction of Trade Statistics, Balance of Payment Statistics Government Financial Statistics. The OECD Main Economic Indicators are also available but no update has been made since the 1989 issue. For information on access mail

Data General Archive for Financial Data

This archive collects any financial and investment data that is in the public domain. Currently, close-of-day quotes are available for approximately 310 stocks. It is hoped that a larger base of contributions will be made from people on the Internet and other organisations. The archive also contains some programmes that are used to treat the data. The URL is Mail for further information.


This service offers daily data on prices shares and options traded on the Vienna stock exchange since February 1993. The service is updated daily. It also contains the trading volume for the previous day. It can be reached as telnet:// The system operates in German.

Journal Archives

There are now two archives maintained by academic journals for the storage of datasets. The Journal of Economics and Business Statistics (JBES) pioneered with the opening of a site in There is a separate directory for each issue of the journal, and within each issue there are subdirectories that have the names of the author(s) of the paper the datasets stored are used to. Mail for further infomation on this site. In January 1994 the Journal of Applied Econometrics introduced a similar requirement that authors of empirical papers submit their data to the ftp archive The structure of this archive mimics the JBES site. It is intended to hold copies of the data sets used in all articles published in the journal, unless it is impractical to do so. For example, data sets that are confidential or extremely large would not be uploaded.

European Commission Host Organisation (ECHO)

ECHO is a gateway to about 30 databases of European Community databases in Luxemburg. Most of them deal with research and development. They can all be queried by the same interogation language called CCL, for which extensive online help is provided. The datasets which are of most interest to economists include EMIRE on employment and employment law, TED on tender information and CORDIS on the commission's R\&D activity. The system is accessible via telnet; the URL is telnet://

4.3.2.Literature Services

This is the part of Internet services where we will expect to see the most important growth in traffic and the area where the effect of the Internet on the profession will probably be the most important. The first bibliographical services on the Internet were Library catalogues. Today most large academic libraries have their catalogue on the Internet. A good collection of these can be accessed via gopher:// (See also Barron and Mahe (1993)). British users should note that the British Library of Political and Economic Science can be reached as telnet://

A more recent development are services collecting either references of new working papers or even the actual working papers in electronic form. Mostly these are available as TeX or PostScript files. PostScript files are particularly easy to create since almost every major word processing program is able to generate them, and they can be printed on any PostScript printer without further processing. Therefore some universities have started in the last years to make their working papers also available in electronic form.


This is a group of projects that try to make the network more useful to the academic community in Economics. The first project is BibEc, a collection of references to printed publications in Economics, mainly working papers. Most of the information on new papers received is mailed to the corryfee mailing list, and loaded on a gopher server where it can be searched. The bulk of the bilbliographical information is provided by a large collection of working papers held at Universite de Montreal.
The National Bureau of Economic Research, the Centre for Economic Policy Research and a number of other, smaller institutions directly submit data on new working papers to BibEc. In December 1993, the United States Federal Reserve Boards added the contents of their "Fed in Print" database into BibEc. There are now about 30,000 papers and articles catalogued in BibEc. A second project that was opened in April 1993 is called WoPEc. This stands for working papers in Economics, but it could accomodate for any type of electronic publication. WoPEc defines an electronic publication as a PostScript file that is accessible via anonymous ftp.
WoPEc has two complementary aims. The first is to provide a home for electronic papers, i.e.a site to which people can upload their papers. These papers can be found on and its subdirectories. The second is to bring together bibliographic information about publications available at other servers so that they can be searched together. For example the papers from the 1994 Bank Structure conference that where made availbable via ftp at the Federal Reserve Bank of Chicago are accessible via WoPEc.
The most recent NetEc project is CodEc, founded in April 1994. It aims to publish computer code that is useful for Economists. The code can be be binary or source, or it can be a set of scripts/macros for other packages. Right now there are only a few programmes available. NetEc can be reached as gopher:// You can also use telnet://, but under this access not all facilities are available.

WUSTL Economics Working Paper Archive

This archive was opened in August 1993. On this server papers are classified according to the Journal of Economic Literature's classification scheme. There are two special subject areas "test" (for test postings) and "meet" for conference papers. The original software was written for TeX and LaTeX and that remains the primary submission form on this archive. PostScript papers are also accepted, as are binary files and wordprocessor files. The archive is best accessed as gopher://, and the gopher can be called via telnet as telnet://, or via WWW as For further information mail the word help in the subject header to

The Post-Keynesian archive

This archive is linked to the pkt mailing list we reviewed in section 4.1.7. In gopher:// working papers written by list members are collected. Each author obtains a directory in which she can store her papers. There is some bibliographic information attached to most papers but the format and contents varies between individual authors. WoPEc is making {missing text - see journal........} include Projects under Development, Evaluation Reports, Staff Appraisal Reports, Country Economic and Sector Work reports, Sectoral Policy Papers, Environmental Data Sheets and National Environmental Action Plans. There is also some bibliographic information on the world banks official publications. The service can be reached as gopher:// or on WWW as

Federal Reserve Bank of Philadelphia

This gopher site has been opened to distribute information about the publication of this bank. Working papers of its staff were not yet available at the time of writing. The URL is gopher://

4.2.3.General gopher and WWW servers

Technische Universitaet Berlin The Economics Gopher Server at gopher://otto.ww.TU-Berlin.DE [Update: no longer active - Web editor] houses the most comprehensive link collection for Economics in Europe. The examples in the earlier section were taken from this gopher and all gopher resources mentioned in this survey can be reached via Berlin. It mirrors parts of the NetEc system and several data archives from the US. In Spring 1994 a job section was started that contains current job openings for economists. For information about submission to this section mail gopher@otto.ww.TU-Berlin.DE. There are also collections relating to politics and mathematics. In the mathematics directory archives of the "Mathgroup" mailing list are kept. This list is concerned with any aspect of the computational software Mathematica.

Sam Houston State University Gopher

This is the mother of all economics gophers servers. It has become a key site for Economics because it has the largest collection of links to services in the world. All the gopher-based services mentioned in this survey can be reached via this gopher. In addition there are a number services maintained at the site. One is a directory of e-mail addresses of economists, others are archives for the Cybercronicle of Political Economy and the mailing lists that are kept by Sam Houston State University, as well as copies of material from other gophers and ftp sites. There is also an extensive collection of TeX related material. The URL is gopher://

The National Bureau of Economic Research

Their gopher was opened in 1993 to complement the ftp site that had already existed earlier for the Penn World Tables. The Penn World Tables (see Summers and Heston (1991)) provide comparative macroeconomic data on a purchasing power parity base for about 150 countries. Other datasets available include the Survey of Consumer Finance, a dataset on trade and immigration by Abowd and Freeman (1990), as well as data from Barro (1989) and Wolf on economic growth. Use the URL gopher:// or

University of Missouri at Saint Louis

This is a comprehensive gopher server for US government information. It contains the Economic Report to the President, the North American Free Trade Agreement, the country reports on economic policy and trade practices by the State Department, the US industrial outlook, the US Census and numerous other documents and datasets. The server should be accessed as gopher://

The United Nations

This gopher contains press releases and data on publications by or about the United Nations and in particular about the United Nations Confernce on Environment and Development and the United Nations Development Programme. The server can be reached using gopher://

The University of Michigan

has two servers that have material related to Economics. The main server, gopher:// contains the copy of the Ecomomic Bulletin Board that we mentioned earlier, the US budget, and documents related to the North American Free Trade agreement. A second gopher is kept on gopher:// Here we find University of Michigan discussion papers, some bibliographies and a set of BibTeX macros for economics journals. There is also a collection on the Economics of the Internet.

The CTI Centre for Economics

CTI stands for Computers in Teaching Initiative, and there are a number of subject-based centres funded by HM government. This server is the first dedicated WWW server for Economics in the world, it opened in May 1994. It holds information about the Centre's activities. Electronic copies of CHEER (Computers in Higher Education Economics Review) are being made available. The URL is

4.4. Academic projects on the Internet

Central European Regional Research Organistion (CERRO)

CERRO is a common project of the University of Economics in Vienn a, the Slovak Academy of Sciences, and the University of North Carolina at Chapel Hill. The project focuses on economic and political aspects of the central European region. The CERRO archive contains discussion papers, papers given at an email conference on East-West integration, archives of the e-europe mailing list, and some data from the region, for example on the hungarian stock market. The archive is at gopher://

The Cliometric Society

has a gopher server at gopher:// that contain information about members, events, abtracts, course syllabi, and some historical datasets. The server can also be accessed as telnet:// Mail for further information.

Iowa Electronic markets

allow people to trade contracts over the Internet. Each person can invest between $5 and $500. Trading is continous and takes place via telnet to telnet:// There are political markets where the value of the fundamental depends on electoral results, and there are financial markets where the contract value at liquidation depends on the value of a financial asset. For further information mail

Financial Economics Network

This organisation was founded in autumn 1993 and now concentates on the publication of a series of e-mail messages called the "Journal of Financial Abstracts" that list abstracts of new publications in finance. It intends to become a fee based service. Mail for further information.

5. The Impact of the Internet on Academic Research

This survey has only been able to show some of the Internet resources for economists. There are many more, and the number of available services is growing with a tremdous speed. Most of this growth is rather chaotic: services appear, change hosts and disappear. Most of the work is done by a few volunteers. Most of them are enthusiastic and achieve quite astonishing results in their work. On the other hand most economists don't know about resources or are reluctant to use them. Will this change in the near future?

The advantages of the Internet are mainly its decentralised nature, the speed of data transmission and the possibility to access any resource in the world from any place. This makes it very easy for each institution to set up services for the distribution of its research results, be it ftp archives for working papers or data sets, mailing lists for their research programmes or gopher and WWW servers for structured information. We would therefore expect that the number of these decentralised services continues to increase.

With a rather long publication lag for many journals working papers have become very important for the research process in economics in recent years. Handling paper requests, copying and shiping the papers already requires a considerable amount of time and funds in many departments. Here local working paper archives are probably a cost-decreasing alternative and we would therefore expect their number to increase in the near future. The same applies to data sets---at least those that do not have copyright restrictions imposed upon them---which can be made available in this way for further research.

The availability of journal articles over the Internet or the foundation of new, purely electronic journals, might be something for the more distant future. Since published journals are sold, payment schemes for electronic documents would have to be imposed for the electronic retrieval of articles. Not many institutions have so far experimented with charging Internet users for resource utilisation. If journal publishers would charge for electronic publications, authors---who receive no payment under the traditional system---will have incentives to switch publications to free sites. Therefore another, totally different publication procedure might be possible. One could, for example, establish refereed electronic journals, where the submittants are required to pay a fee for the referee process. The paper, if accepted, might then be available for free over the Internet.

However, a lot depends on the technical and economic development of the Internet. In the current situation, Internet users use it at zero marginal cost. If this pricing structure changes, the face of the Internet will undoubtably change but it is difficult to predict what the effect on volunteer services will be.

The decentral organisation of the Internet will in our view also inhibit some developments. Every central service that relies upon many local services, as for example special topic gopher and WWW servers or hypertext documents, is very vulnerable to changes in the local services. It requires a tremendous amount of work to update links, search for new information and follow databases over several hosts. The size of special topic services will remain restricted by the resources an institution can devote to their updating. If the available bandwidth increases through projects like the US' information highway or the UK's SuperJanet, we would expect that only those link collecting services to survive, that are able to devote sufficient resources to updating. All users would connect to these services to access information.

Thomas Krichel University of Surrey
Thorsten Wichmann Technische Universitaet Berlin


Abowd John. W. and Richard Freeman (1990): The internationalisation of the US labor market, NBER working paper no. 3321.

Barro, Robert J. (1989): Economic Growth in a Cross Section of Countries, working paper, University of Rochester.

Barron, Billy and Marie-Christine Mahe (1993): Accessing On-Line Bibliographic Databases, [URL: file://].

Berners-Lee, Tim (1994): Uniform Resource Locators, Internet draft, [URL:].

Kehoe Brendan P. (1992): Zen and the Art of the Internet: A Beginner's Guide to the Internet, 2nd. Edition, Englewood Cliffs, NJ: Prentice-Hall.

Gaffin, Adam & Jorg Heitkotter (1993): Big Dummy's Guide to theInternet---A Round Trip Through Global Networks, Life in Cyberspace, and Everything\dots, [URL:file://].

Goffe, William L., (1994): Resources for Economists on the Internet, [URL: gopher://].

Kehoe, Brendan P. (1992) Zen and the Art of the Internet: A Beginner's Guide to the Internet. "nd edn Englewood Cliffs, NJ: Prentice-Hall.

Krichel, Thomas and Thorsten Wichmann (1994): Internet Primer for Econo-mists: An Update, Computers in Higher Education Economics Review, no.23, November.

Kroll, Ed (1994): The Whole Internet---User's Guide and Catalog, 2nd ed., Sebastopol, CA:O'Reilly & Associates.

LaQuey, Tracy and Jeanne C. Ryer (1993): The Internet Companion - A Beginner's Guide to Global Networking, Addison-Wesley.

Lindner Paul (Ed.) (1993): The Internet Gopher User's Guide, University of Minnesota, [URL:gopher://]

MacKie-Mason, Jeffrey and Hal Varian (1994): Economic FAQs About the Internet, [URL:gopher://]

Summers, Robert and Alan Heston (1991): The Penn World Table (Mark 5): An Expanded Set of International Comparisons, in: The Quarterly Journal of Economics 106, p. 327--368.