It is a regular complaint - and not just about banks - than when the bonuses are handed out it’s men who gain the lion’s share of them. Women come very much second place in this race. As ever with such events we want to know which type of discrimination this is.

Taste discrimination on the grounds of gender - except among the truly extreme fringe we except things like affairs of the heart and body from such strictures - is considered to be verboten these days. But rational discrimination, people might complain but it is still accepted as being logically valid.

So, paying bonuses largely to men an not to women, which type of discrimination is this?

Male workers put in less effort at work when bonuses are cut and replaced with fixed pay, but women work just as hard either way.

Men slack off to such an extent that academics found a 12pc drop in effort in an experiment moving from piece rate payment - that is, being paid for each piece of work done - to a fixed rate.

As ever with such measurements we have to note again that “men” an “women” here dos not refer to any individual, we are talking about average differences across the populations. As in it is not true that all women are bad at physics - today saw part of the Nobel go to a woman - nor that all men are good at it - large numbers of men today did not get a share of the physics Nobel - but that skill at, or perhaps interest in, is not equally distributed across the populations of men and women.

But bonuses appear to be less effective at motivating women and more so at men. Thus it seems obvious enough that a rational employer will direct bonuses at men as that’s where they work.

If you’d like it in another manner, women are mature and men require extra sweeties to put the effort in. This being true then how would you distribute the sweeties?