We want to limit the exploitation of the fiscal capacity of the richer regions by keeping down the rate of immigration to a level that would be meaningful and efficient. One way to do that is to have a scheme of equalization which essential bribes people to stay in the poorer regions.

You can get a coalition of senators from particular states in America, for example, who want to construct highways or dams or ports which may well be very inefficient. The taxes would be paid by the people over the whole country, but the benefits would go to the few people in those particular locations. This type of spending is a rather gross waste of resources that worsened over the years as the government has been allowed to do more particularized things.

Politics is a romantic search for the good and the true and the beautiful.

Imagine that Queen Elizabeth I, in her time, had the opportunity to give out a monopoly for playing cards within the kingdom. She knew she was going to give it to one of her courtiers. These courtiers would then all try to curry her favour. Meanwhile, they would not contribute anything to the product of the kingdom, in fact, they were wasting resources trying to secure a single prize. That, more or less, is rent seeking.

It is much more difficult to get implemented politically what might be desirable economically. Even if you came out with an economic argument in favor of equalization - and I think there are arguments on both sides - I would still come down in favour of some sort of a scheme on strict economic grounds.

People share a universal behavioural trait: if there are profits to be made, the effort to get that money will attract investment. This is true in the private sector, the market sector, as well as the public sector.

If you have an area where high-income receivers concentrate, you have a higher fiscal capacity. That fiscal capacity is a valuable resource and will create rent-seeking. People will trying to get that resource one way or the other, including immigration. It is very much like the medieval peasants putting their sheep on the commons pasture. It is better than the open range, and if you let them have open access they will, in fact, put too many sheep on the pasture and waste the value that the pasture has.