During the postwar period, many countries have de-tracked their secondary schools, based on the view that early tracking was unfair. What are the efficiency costs, if any, of de- tracking schools? To answer this question, we develop a two skills - two jobs model with a frictional labour market,...

We model individual careers in sports and games from initial entry to eventual exit or success as a discrete - choice, finite - horizon optimization problem. We apply this model to the international game of chess and study cross - country differences in the relative success of players. While we...