Wednesday 11 September 2013

Changing attitudes to benefits?

This should be a very quick post. There were a couple of articles in the Guardian yesterday on the British Social Attitudes Survery [1][2]. Here are some quotes:

"The percentage of Britons believing that "benefits for unemployed people are too high and discourage work" has seen the biggest fall in thirty years"

"Since last year, and perhaps in stark contradiction to most people's expectations, attitudes towards benefit claimants have become strikingly more sympathetic. The difference in the 2012 findings is the largest single change on this scale since the survey began. Last year 62% felt that benefits were too high and discouraged work. This year that has dropped to 52%."

So let's look at the data.

On the x-axis we have year and the y-axis the percentage of people agree with either the statement "benefits for unemployed people are too high and discourage work" (in green) or "benefits for unemployed people are too low and cause hardship" (in blue).

The 'softening' in attitudes the quotes are referring to is the change from 2011 to 2012 (look at the dip in the green line at the far right of the graph). This is technically correct, but come on, there is signal and there is noise. Compared to the overall trend over the past 25 years it seems like the journalists are clutching at straws. Of course, this dip could be meaningful, but it is impossible to tell from 2 data points. If the trend continues next year then we might be able to start discussing it.

As an example, here are two curves fitted to the data set. For the geeks, the first is a polynomial of degree 2 (quadratic; left panel) and the second of degree 3 (cubic; right panel). The dots are the actual data, the lines the fitted curves.

The only point I want to make is that the lines (fitted curves) go either up or down at the end depending on the particular model. I did this analysis in 5 minutes in MATLAB (the polyfit function for those interested) so it is obviously crude. In short, we don't really know if the change from 2011-2012 will continue in the same direction or even reverse next year.

At this point I should add that both journalists provided caveats to their original statements by saying:

"Although this is the biggest softening in attitudes so far, it doesn't represent the highest level of support for benefits to the unemployed. In fact, looking at all three decades of data reveals a very different picture of how attitudes to welfare have changed."

"I would urge caution. As the Guardian's Data Blog shows this morning, the graph on this question is what statisticians call, in technical jargon, a spiky little bugger." 

My only point is that both pieces seemed to lead with noise and caveat with the signal. The latter should be the focus and the former worthy of note, not the other way round.

No comments:

Post a Comment