He sums up his views as follows:
1. Economics is not an exact science. Its substantive claims can only ever be more or less probable, though that probability can sometimes confer knowledge.
2. So: absolutely categorical statements—statements like “all of the interest rate differential was due to low economic activity, and none due to government policy” or “Plan A is failing” cannot be purely economic in character.
3. Those in positions of public authority should be capable of being held to account. This applies to politicians of course—but also to civil servants and academics.
4. As Director of NIESR, Jonathan is in a position of public authority. Indeed NIESR is an academic institution (NB its website is www.niesr.ac.uk), and so subject to academic standards of rigour; as well as partly or wholly funded by public money.
There is no disagreement on (3) and (4), although note that his arguments apply to all academics (like me and other academic bloggers) and not just directors of well known public institutions. I would also agree with (1), if claims are about the real world rather than models of the real world. So Dr. Norman’s problem, to paraphrase, is that Jonathan should have said ‘Plan A is probably failing’ rather than ‘Plan A is failing’.
Does this mean that in future posts I should insert a ‘probably’ in any statement that makes a claim about the real world? Take some recent news, like figures released today showing UK earnings rising at 1.4%, compared with inflation over the same period of 3.5%. Instead of writing
“This decline in real wages is due to the high level of unemployment, caused by the recession that followed the financial crisis. Workers are suffering today because of irresponsible behaviour by the banks before the crisis.”
I should, to preserve academic standards, write
“This decline in real wages is probably due, at least in part, to the high level of unemployment. This in turn may have something to do with the recession, although we cannot rule out that other factors are at play. The recession itself could well have been triggered by a global financial crisis, although we can never know this for sure. Some people suggest that this crisis reflected poor lending decisions by banks, so there just might be some connection between irresponsible behaviour by banks before the crisis and people’s declining wages today. However it is all very uncertain.”
Would you class the second as economics, but the first as a political attack on the banks?
So why is Dr. Norman so keen that I or Jonathan Portes insert all these qualifiers to what we write? Well lets just imagine what might happen if I take Dr. Norman’s advice, and if I am ever asked to appear in front of the Treasury Select Committee again.
Wren-Lewis: “In my view Plan A has probably failed”
Conservative MP: “But you cannot say for sure - you admit it is possible it has worked”
Wren-lewis: “Well of course, but I think the balance of probability is that it has failed”
Conservative MP: “Ah, the balance of probability. Would you care to put a number on that professor?”
Wren-Lewis: “Well that is very difficult to do, but my guess is that the probability that it has failed is over 95%”
Conservative MP: “Your guess! My dear professor, I suggest you stop guessing and come back to this committee when you have something a little better than guesswork. In the meantime, I can tell you that Plan A has clearly worked, and I can say that without qualification.”
What I find revealing about all this is that while I am supposed to say ‘Plan A has probably failed’ as an academic economist, it is OK to say ‘Plan A has failed’ as a political statement. Political statements, apparently, do not need qualification even when qualification is due. Is this because they have no truth value whatsoever? Perhaps this was what was going on when certain well known US economists claimed that “the negative effect of the administration’s ‘stimulus’ policies has been documented in a number of empirical studies.” Here it did not matter that nearly all such studies had found the stimulus policy had been effective, because it should have been understood that here they were making a ‘political statement’, which should not be confused with the ‘economic statements’ they normally make. (Fortunately members of the Conservative Party have not as yet started making ‘political statements’ denying evolution, although climate change denial is doing pretty well.)
The reality of course is that most people now realise Plan A has failed, and those that cannot admit that only have low interest rates to point to as any kind of success. So when macroeconomists point out that interest rates would be expected to be low for an economy that is so depressed, and that the experience of certain Eurozone countries just does not apply to us, these economists become dangerous voices that need either to be discredited as partisan, or intimidated into silence. Such tactics can be quite effective when used against an organisation as timid as the BBC: lets see if it can also work with an institution like NIESR.
 The more normal criticism by politicians of economists is the opposite, which is that we are always hedging. ‘Give me a one-handed economist’ President Harry Truman is reported as saying.