Wednesday, September 21, 2011
The public goods game is an explanation to why so often too little is done to promote the common cause. The idea itself is very simple. Imagine we have several players. Everyone can decide how much resources to put into the "common pot". Next, the content of the pot is multiplied (by a number less then the number of players) and distributed evenly back to all the players. Obviously, the best solution for everyone were to invest a lot and gain back even more. Unfortunately, for every dollar I invest, I receive back less than one (although I receive a slice of what the others have invested). Hence, a rational selfish player will not invest anything at all and solely free-ride on the others investments. As experiments indicate, the people around us are not quite that bad, but most will still devote less than optimal amount of resources for the public good.
Now imagine that instead of players, we have countries. The common pot are the public goods, such as crime prevention or public highways. Voters in every country are free to pay taxes and build up such public goods. But afterwards, they are also free to move to whichever country they want. What would rational voters do? First, they would pay no taxes, and second, they will move to the country with best amenities. Sounds like the public goods game, right?
However, for the analogy to work, the public goods must be non-excludable -- it must be hard to avoid free-riding on the taxpayers bill. However, from the viewpoint of immigration, many public goods, usually given as examples of non-excludable goods, are actually excludable. This includes highways (can be financed by fuel taxes), social security (can be made conditional on some sort of contribution period) and public schools (if immigrants can be taxes, this money can by used for constructing new schools). If population growth (not just through immigration) is slow enough, and newcomers pay taxes, you can expand all of the above examples. The excludability originates from the fact that governments can tax the (potential) users, and expand the supply through this source of funding. Note that you still may have a conflict between rather rich locals and poor immigrants, each preferring a different level and variety of goods.
What cannot be easily expand include some sort of inherently limited resources one cannot produce at all, such as minerals, arable land, but also street space in a busy downtown. Although these are public goods as well, the public goods game as described above does not directly apply for these (another one, called "tragedy of commons", does). There is also a type of amenities which are non-excludable even in case of countries and governments. This includes information, environment protection, and other stuff for which national borders play no role.
In conclusion, free-riding on public goods provided by locals is a valid but possibly quite weak argument against liberal immigration policy. Strength of it depends on the degree to which the immigrant population can be taxed, i.e. whether immigrants are in legal employment.
Note also that there are more ways immigration and public goods provision are related. For instance, studies find that more diverse population leads to less public goods provision, possibly through low level of solidarity in heterogeneous society. That's a different story, however.