This paper studies why illegal immigration is widespread. We develop a political agency model in which a politician decides on an immigration target and its enforcement, facing uncertainty on the supply of migrants. Illegal immigration can arise for two reasons: the policy maker may be unable to...

Over the last decade, many countries have experienced dramatic increases in university enrolment, which, when not matched by compensating increases in other inputs, have resulted in larger class sizes. Using administrative records from a leading UK university, we present evidence on the effects...