Because the advice of economists is so hopeless, you may say. Well think about the following thought experiment. After the financial crisis. suppose people had done the opposite of what the majority of economists said they should do. We do not need to imagine over Brexit, because most of the 52% who voted for Brexit chose to ignore, or more likely did not hear, the advice of 90+% of economists that Brexit would make them worse off. For those who work that belief was quickly shattered as their real wages fell as a direct result of Brexit.
Immediately after the financial crisis interest rates would not have been cut and austerity would have started in 2009, not 2010. Banks would have gone bust because economists said we needed to bail them out. In which case the Great Recession would have become the second Great Depression. Because the majority of economists did not support austerity you would have had continuing cuts in spending during this new depression.
So comparing this thought experiment with reality, we can see that economists have prevented a rerun of the 1930s depression, and if their majority advice had been taken we would have had a stronger recovery and the UK would not have left the EU. Sounds pretty good to me. But, as I’m sure you are now saying, what about the financial crisis the economists failed to warn of?
That was a mistake, but what are the consequences? Do you really think that if most economists had warned about how fragile the sector was anything would have happened? Banks would have continued to lend because they were making money and they had a guaranteed bail out from the state. Their campaign contributions would have weighed far more heavily in politicians’ minds than warnings from economists. So yes, not warning about the financial crisis was a mistake, but it would not have changed anything if the mistake had not happened. Economists are often told to stop being naive about politics, but the same needs to be said to their critics.
Despite such a strong record in macroeconomics since the crisis, why does economics get so much stick? I think there are three reasons. The first is simple: when the economy goes wrong, economists are easy to blame, particularly because of those forecasts that never predict downturns. In reality virtually no academic macroeconomists are involved in forecasting because they know that kind of unconditional forecasting is a mugs game , and furthermore most economists are not macroeconomists, but for some that kind of detail is irrelevant. (There are also plenty of highly successful pieces of microeconomics, but most critics act as if economics was just macroeconomics.)
The second reason is politics. Carlyle in 1849 called economics the dismal science because economists did not support his idea of reintroducing slavery. Ever since then economics has annoyed politicians and their supporters of various colours by pointing out the problems with various political programmes or schemes.
Politics is also at the heart of the third reason for criticism: politicians and ideologies of the right use the aspects of economics that suits their cause. Want to promote markets? Just take the idea from economics that an ideal market is an optimal way of exchanging goods, and ignore all the ways that real markets deviate from this ideal (ways which, incidentally, a great many economists spend a lot of their time studying). Some heterodox economists of the left, rather than use mainstream economics to point out how the right plays fast and loose with economic ideas, prefer to suggest that mainstream economics is much closer to the right wing caricature than it is in reality. It is why, as Noah Smith observes, so much of this criticism can be found in the pages of the Guardian.
This misrepresentation of mainstream economics is either deliberate or reflects ignorance. Ignorance about the fact that a lot of economics has become more empirical and therefore more eclectic in its use of theory over the last few decades, perhaps in part because of the influence of behavioural economics. Ignorance that even in macroeconomics, where ideological influences can be strong, there is more consensus around New Keynesian economics than some mainstream Keynesian economists imagine. (See my survey with André Moreira of post graduate teaching at the top schools here.) Nowadays you will find that in most areas of economics (alas not yet macro so much) there is nothing limiting the analysis to selfish individualistic behaviour. The idea that economics is like a religion is absurd.
But sometimes it is hard not to believe that popular criticisms of economics choose to ignore how far economics deviates from the neoliberal characterture. There is no excuse for ignoring that, for example, the best arguments against health care being left to the market can be found in a paper by Nobel prize winning economist Kenneth Arrow written decades ago. As the recent book by Colin Crouch suggests, the best critiques of neoliberalism come from within economics.
Another ridiculous charge against economics is that economics has a natural bias against state intervention. Indeed it is possible to argue the opposite. In my own field it is typical to assume the existence of a benevolent policy maker, who maximises social welfare. It is essentially just a useful analytical device, but you could argue if you wished to that this device biases those that use it to favour state intervention.
Judging by recent conversations I have had, many heterodox economists attack the mainstream because it uses the distinction between positive (value free) and normative economics. An example of positive economics would be me saying a temporary cut in government spending when interest rates are stuck at their lower bound reduces output. A normative statement would be that austerity is unfair. Heterodox economists like Sheila Dow seem to suggest that everything is value laden, and the positive/normative distinction allows economists to avoid being “morally implicated in the advice they give.”
I think this criticism is either trivial (yes, of course there may be normative reasons for choosing particular research topics) or dangerous. It is dangerous if it suggests that economists should be encouraged to base their analysis on assumptions that reflect their values. Economics, even though it is a social science, should conform to the scientific method: it should be as much like a science as medicine. Indeed I think it would greatly improve the public debate if both economists and their critics realised that economics, even though it is a unique and inexact science, is more like medicine than any of the hard sciences.
Dow writes “Getting policy-makers or the general public onside over a particular argument is therefore, critically, a matter of persuasion rather than demonstrable proof (since that proof is impossible).” But surely the best way of trying to persuade a policymaker not to impose austerity is to say that most models, including the consensus theoretical model, and nearly all the evidence suggests austerity will reduce output. In contrast it is far too easy to persuade a politician of things they want to hear. We do not want politicians to pick advice only if it is given by ‘one of us’ (by those who share their values), or as a result of the rhetorical skills of the academic.
The danger in encouraging plurality is that you make it much easier for politicians to select the advice they like, because there is almost certain to be a school of thought that gives the ‘right’ answers from the politicians point of view. The point is obvious once you make the comparison to medicine. Don’t like the idea of vaccination? Pick an expert from the anti-vaccination medical school. The lesson of the last seven years, in the UK in particular, is that we want mainstream economists to have more influence on politicians and the public, and not to dilute this influence through a plurality of schools of thought.
All this does not mean that economists are beyond criticism. As my last post pointed out, I have fundamental criticisms about current macroeconomic methodology. An important point to note about the microfoundations methodology is that it excludes economists who are not prepared to sign up to what is currently considered (by macroeconomists) acceptable microeconomics, or who do not think microfoundations is where you have to start in doing macro. But this critique has nothing to do with values. The mistake macroeconomics made in the 1980s was not in their desire to look for microfoundations, but in deciding that models that had internally consistent microfoundations were the only admissible models.
The big problem with most criticisms of economics you see in the media is not that economics is beyond criticism: as the paragraph above suggests it in many cases should be criticised, and there are plenty more interesting criticisms of economics available. The problem is that these more important criticisms are not those you find in the pages of the Guardian. The typical criticisms you see in the press are just not very good, and I fear reflect either ignorance or ideological antipathy.
 A lot of the criticisms of forecasters are themselves spurious. Someone who writes “economists should not need to pretend that we can predict things that do not really matter to several decimal places” are themselves pretending that there are any serious forecasters who do pretend this.