Here's another recent finding in experimental economics:
We analyze how tax evasion is affected when the same income is earned without any effort, or with a moderate or high level of effort.We find that subjects who have invested high levels of time and effort evade significantly more taxes.
In other words, people who feel more entitled to their income, by virtue of sweating for it, are more likely to try to keep it.
You might think this unsurprising .But I think it highlights something I've said before - that neoliberalism is performative; it doesn't just describe the world, but creates it.
One claim of neoliberalism is that individuals are entitled to their incomes, as these are the result of work and contribution to society rather than to, say, luck or accidents of history. If people believe this, then they will have lower tax morale, and so will try to dodge taxes either legally or not. The neoliberal claim that higher tax rates reduce revenues will therefore be true. But this will be only so by virtue of people believing they are entitled to their incomes. Neoliberalism then becomes a self-fulfilling belief equilibrium*.
But we can imagine an alternative equilibrium - in fact we don't need to imagine it, as it has existed in some social democratic societies. In this, people regard their high incomes as a product of good luck, and feel obliged to share this fortune. As a result, they tolerate high taxes. In this world, the social democratic claim that high taxes don't reduce effort is true - but, again, only by virtue of people's prior beliefs.
This poses the questions: is it possible to shift the belief equilibrium away from the neoliberal to the social democratic one, and if so how?
It's in this context that we should interpret MPs' haranguing of companies for "immoral" but legal tax-dodging.
From one perspective, such finger-pointing makes no sense; if Labour MPs think companies should pay more tax, they should have changed the law during the 13 years they were in office. However, what they are trying to do is change social norms by stigmatizing tax dodging. This is more than reasonable. It is only by having norms which raise tax morale that higher tax rates can be reconciled with economic efficiency.
Whether MPs alone have the power to change norms is, however, another matter.
* The same might be true for corporate taxes. In a neoliberal world where managers' duty to maximize "shareholder value" is interpreted as narrow short-term profit maximization, we'll see more corporate tax dodging than we would in a world where social norms frown upon agressive tax planning with the result that companies who engage in it alienate customers and so suffer a loss of business.