not all countries have the same
political structure of democracy that
the UK has the Joseph Stalin once said
of his own country those who cast the
votes decide nothing those who count the
votes decide everything but where you
have a genuine political democracy there
will always be politicians anxious to
know what the electorate thinks so that
they can tailor their policies to
reflect those concerns when I go knock
on doors as I do on a regular basis I
find a package of things people are
interested in and it tends to be the
economy it tends to be making sure we've
got a good health system a good
education system a good welfare system
for people who've fallen on difficult
times good support for people who find
it difficult to look after themselves
perhaps through disability and a real
thirst and an importance attached to
environmental issues but it's difficult
to be sure what issues people regard as
being of greatest importance to you most
have many concerns how do they ring one
way to do it is to have a surveyor to
ask people give them save ten major
concerns and ask them to rank those
concerns in order of importance I just
wanted to ask if you can rank decisions
in order of importance to you the
results are much as you might expect in
our survey the top ten matters contained
no real surprises at all we know that we
only need to interview a relatively
small number of people to be fairly sure
what the whole electorate thinks but
that only takes us so far unfortunately
different groups within electorates
attach different weights to different
issues it's clear for example that some
issues have a higher priority among
young voters others among older groups
what would be useful to know is the
issues that each group regards is
important if there are substantial
differences politicians can target
different groups with different messages
if everyone thinks the same then this
won't be necessary that if you look at
the attitudes of 12 to 15 year olds and
you ask them what are the issues that
they're concerned about the environment
was coming up number one but if you look
at the 18 to 24 year olds it was down
around eighth place and then it came
back in the slightly older age group as
they had their family formations and
they were having children so they were
worrying about what kind of a world were
bringing our kids up in but the 18 to 24
year olds were worried about getting a
job getting on in life of finding a
boyfriend or a girlfriend and so that's
explained the difference between the age
cohorts gene your priorities will change
over the next 20 or 30 years yeah
definitely seems I got a job or a family
everything's good at a full-time job
depends what sort of sex what sector I'm
working in of course yeah definitely
definitely change yeah your views do
change I think that the way people vote
changes as you get older it may be that
the concerns of younger people are quite
different from the concerns of older
people one way we can test that is to do
a survey so we asked some under 40s and
some over forties to rank a whole load
of issues in order of importance to them
well education obviously because of I'm
a first-year obviously being a student
yeah that that was the first thing I
kind of looked tech service jobs
education health I'll chose employment
obviously I'm a final year student
health care my certainly global woman
has always been an issue it's always
going to be there yes it's gonna it's
not that it's not important it is very
important but it's not exactly going to
be your main focus at the moment I
decided yes so anything that affects us
really
pensions why does that figure soullow in
your and lots of people worried about it
sorry because it's so far away having
established a typical ranking for each
group we then analyzed the results by
developing a rank correlation
coefficient first we'll explain what the
term means then we'll be able to see how
closely linked the two groups are in
their thinking and you'll be able to see
whether there's anything that surprises
you about the results the data we
collected is given in the table we've
ranked the issues according to the views
expressed by the over 40's but whether
we present the survey results ranked by
over 40's or under 40 s the coefficient
will be the same we haven't got a large
enough sample for statistical
significance so we can't read too much
into the result but we're interested
here in the method of analyzing the
results not in their collection
will shortly see how close the two
groups are in their rankings using
spearman's formula the formula is R sub
s equals one minus six sigma d squared
over n times n squared minus one
now before we work it out let's make
sure we understand the significance of
the number that will obtain if there
were a perfect positive correlation of
the kind shown below then with this
formula we would attain a score of +1
the rankings of the two groups would be
identical
if there was a score of minus one it
would be because there was a perfect
negative correlation each groups ranking
being the complete opposite of the other
in our case given the over 40's ranking
the under forties rank would have health
as ten pensions at nine and so on
and this is how that would look
diagrammatically
now we've plotted our actual data
it's clear that we don't have either a
perfect positive or a perfect negative
correlation but it isn't easy to see if
there's at least some positive
correlation some negative correlation or
no correlation at all but our formula
will tell us what we can't see clearly
with a naked eye now we're in a position
to work out the correlation coefficient
using the formula and see how we can use
this information to help politicians
target their message and let's be clear
whatever they say the politicians do
care about these things it depends on
who they're talking to if they're
talking to the television or to a public
audience they don't believe in opinion
polls if they're talking in private they
believe them beyond all recognition and
the third one if they change their
policies I'm delighted because it says
they're listening to public opinion and
if they're not there to represent the
public what are they doing in Parliament
we're ready to work out the correlation
coefficient using our formula we can
then see how this might give help to the
politicians seeking to understand
people's wishes we begin our calculation
by computing the differences in the
rankings for each issue labeled d so in
column for we have for health 1-4 which
gives us minus 3 when we sum these
differences at the bottom of the column
it will of course come to 0 so in column
5 we've squared each of the differences
and then summed these that way we turn
even negative numbers into positive
numbers and that's what we want we're
interested in the absolute differences
of the rankings
in our case the sum of these squared
differences is 202 we can take this
number and feed it into our formula and
so produce our rank correlation
coefficient
our formula is our sub s equals one
minus six sigma d squared over n times n
squared minus one we've worked out that
sigma d squared the sum of the squared
differences is 202 with 10 issues so N
equals 10 so this gives us our sub s
equals one minus six x 202 over 10 times
100 minus 1 which equals one minus 1212
over 990 which equals minus 9.22 for now
this is fairly close to zero suggesting
that our two groups have little in
common when it comes to their views on
the relative importance of the key
issues of the day if our data were to be
representative then a political party
would be in difficulties there's
virtually no correlation between issues
generally of greatest concern among
younger people and issues generally of
greatest concern amongst older people
this makes the task of finding a message
appealing to all age groups very
difficult developing policies on tax and
spending for example becomes very
awkward things can be even more
difficult than this sometimes the
significance of issues can vary between
people in the same group it won't do for
the politicians to take notice of old
surveys people's attitudes can change
quite quickly for example in recent
years green issues have come to the form
huge changes in medical techniques have
brought health care issues more to
people's minds on the other hand better
control of inflation extended to push
this down people's list of worries will
always see Health Services one of the
most important issues will always see of
the economy but we have the economy much
higher today than we
did 10 years ago that's for sure in
people's voting behavior but remember
issues of the not of the eighty percent
but of the twenty percent of floating
voters issues are only the prime
consideration in forty percent of those
now to use some more statistics if you
multiply eighty percent by forty percent
you're down at two percent of the total
electorate that you're talking about and
they're the people who say that the
economy it's the economy stupid so given
the attitude changes that will
inevitably take place every time
questionnaires of this kind I conducted
regularly these techniques of
correlation are clearly useful for
analyzing political data but they have a
wide range of applications whenever in
the social sciences we wish to make
comparisons with sets of rankings
correlation coefficients will prove to
be an improper technique to use but they
do have their limits doesn't tell us
anything about the causal links between
sets of data and secondly when we look
at rank correlation it doesn't tell us
anything about the relative values that
we place on issues for example so we
don't know whether somebody rates issue
number to a bit less important than
issue number one or a great deal less
important but if we're aware of these
limitations then correlation
coefficients can be very useful to us as
a minister in government the way we
approach policymaking is evidence base
and I studied economics at University
and I actually studied statistics to a
certain extent as well and I find I use
those skills now more than ever before
because you're analyzing research to try
and work out really what policy
direction you're going to take and the
effects of the policies that you're
going
the policy decisions that you're making
so statistics has I think a growing role
to play in policymaking
you