Views on the minimum wage show economics to be an inexact science

.The hallmark of a science is not just having refutable hypotheses, but also changing its view when data shows the theory is wrong. Economics is often accused of not being a science. A good test case to see if that is true is the minimum wage. Basic economic theory suggests if you fix wages at above their level in the market, employment will fall as less workers are employed. However a number of empirical studies, the most well known of which was written by Card and Krueger in 1994, have suggested that employment shows no noticeable decline when a minimum wage is imposed or modestly increased. My reading is that the most convincing studies do show this result, but not all do, so the picture is not completely clear.

This illustrates a problem for economics (and all social sciences) that outsides often fail to appreciate. Measurements and econometric studies are often not conclusive, and even in the case of austerity you can find one or two empirical studies which says something different to all the rest. As a result, it is more difficult to use data to show a hypothesis is conclusively wrong in the way the natural sciences can. My own view is that the balance of studies clearly shows a modest minimum wage has no noticeable impact on employment, but others would disagree.

Here is a question from the IGM survey.of around 50 top US economists on the minimum wage

Academic economists appear evenly divided, and few hold a strong opinion on the issue. A similar survey of UK economists, asked about the 2016 increase in the minimum wage, was also divided but lent more towards no effect. In contrast, most German economists appear to have been opposed to the recent introduction of a minimum wage.

If you were cynical you might say that all this shows is that the views of economists just reflect their political opinions, and I would indeed expect there would be a clear correlation to support that with the minimum wage. However when either theory or evidence are pretty clear, economists do not divide by political opinion. The same survey in 2012 and 2014 showed economists largely agreeing that the Obama stimulus reduced unemployment and was beneficial, even though the political right was strongly opposed to it. The reason is that economic theory and nearly all evidence shows that fiscal expansion when interest rates are stuck at their lower bound is expansionary.

Equally standard microeconomic theory is just as clear that the minimum wage will reduce employment, and I suspect that had this survey been done in the early 1990s most academics would have agreed with this, whatever their political persuasion. What has changed is the evidence. This example clearly shows a good number of academics responding to empirical results that conflict with standard theory.

Furthermore some economists have done what good scientists should do and produced new theories which can explain the empirical results that the minimum wage does not reduce employment. In that sense economists have been behaving as a science should. But because there are some contrary studies, that allows two things that distinguish economics from physical sciences. The first thing is a temptation to hold on to basic theory even though the balance of evidence is against it, something that is not totally absent in the physical science either (Kuhn, Lakatos etc). The second is to allow ideological influences to help decide what should be a scientific judgement. These are the senses in which economics is an inexact science.

For those interested in economic methodology, and excellent place to start is here, the title of which I am abusing in this post. However it is also worth reading this for sources on the new 'empirical turn' in economics. On the impact of ideology on economics a great place to start is this thread from Beatrice Cherrier. On the introduction and history of the minimum wage in the UK, including initial political resistance to it, see here.

Misrepresenting academic economists

Brad DeLong entered the debate between myself and Unlearning Economics with a post entitled “The Need for a Reformation of Authority and Hierarchy Among Economists in the Public Sphere”. He writes

“Simon needs to face that fact squarely, rather than to dodge it. The fact is that the "mainstream economists, and most mainstream economists" who were heard in the public sphere were not against austerity, but rather split, with, if anything, louder and larger voices on the pro-austerity side.”

The dodge, and I think it is a pretty good dodge, is that politicians and a good part of the media choose the economists they publicise. If you accept that austerity came from what I call deficit deceit - an attempt to reduce the size of the state using the false pretext of deficit reduction - then obviously politicians and their supporters in the media would choose those economists whose views were useful in promulgating that deceit. As the UK discovered during the Brexit debate, even a tiny proportion of economists (8!) can appear much larger if the media gives them much more attention than they deserve.

But the argument remains a dodge in the following respect. How were people outside economics, including much of the non-partisan media, meant to know that particular academic economists were unrepresentative of the majority? Indeed how can even economists be sure of this? I’ve argued that the majority of academic macroeconomists were always against austerity, particularly once the reason for the Eurozone crisis had been resolved by Paul De Grauwe, but the evidence I use to back this up is piecemeal and indirect (see here, pages 3 to 4).

Part of the problem is a certain disregard for consensus among economists. If you ask most scientists how a particular theory is regarded within their discipline, you will generally get a honest and fairly accurate answer. In contrast economists are less likely to preface a presentation of their work in the media with phrases like ‘untested idea’ or ‘minority view’. In macro it also reflects periods in the past, which still resonate today, when there was deep division and antagonism between different groups. This extends to not being sure what is taught at masters level in the top schools: it turned out, when André Moreira and I did the research, that there was more consensus in one key respect (Chicago excluded) than some had imagined.

Part of Brad’s post it seems to me is simply a lament that Reinhart and Rogoff are not even better economists than they already are. But there is also a very basic information problem: how does any economist, let alone someone who is not an economist, know what the consensus among economists is? How do we know that the people we meet at the conferences we go to are representative or not?

To help fill that gap we have in the US the IGM Economic Experts Panel survey, and in the UK/Europe the CFM survey. (The IGM survey has recently started a European version.) The US IGM survey has asked a question about the Obama stimulus package on more than one occasion, and the latest result is here. It is one key part of the evidence for my claim that most academics were and are against austerity.

However all these surveys share a common feature which I find problematic, and which also reflects on Brad’s concern. They are selective, and deliberately designed to only include the academic elite. IGM writes that panel members are all senior faculty at the most elite research universities in the United States. So they tell us not what academic economists think, but what a chosen sample of ‘elite’ economists think. Now if those samples are well chosen, as I think they mostly are for these surveys, that may not matter too much, but how representative they are can always be questioned. It also gives the impression that it is only this elite that are worth listening to when it comes to policy issues, something I think is simply wrong as well as being elitist.

As part of the build up to the Brexit vote, the Observer newspaper commissioned Ipsos MORI to email all members of the Royal Economic Society. 91% of those who responded thought Brexit would have a negative impact on UK GDP in the longer term. As most UK academic economists are RES members, it was therefore possible to say that there was a clear consensus among academic economists that Brexit was harmful. To be able to say this about all economists, rather than just a select few, in my view strengthens the power of the survey. (Some defend elitist surveys because the elite is ‘influential’, but if they influence their fellow economists that will show up in a larger sample.)

I think the experience with austerity and Brexit suggests it is time for national economics associations (like the RES or AEA) to start representing the opinions of economists by conducting such polls of their members under their own initiative. With email addresses the technology makes it easy to do. It is time these organisations started telling both us and the world about what the consensus (if any) is on key policy issues. It would be an important step towards ending the misrepresentation of economists and economics.