La meilleur de tousles tarifs serait celui qui ferait payer a ceux qui passent sur une voie de communication un peage proportionnel a l'utilite qu'ils retirent du passage.1—Jules Dupuit, 1849.

Economists have paid very little attention to the statistical methods known as "factor analysis" or "component analysis." These methods were developed primarily by psychologists. Sociologists have also used them to some extent. These methods may eventually help economists to solve some of their...

Jobs differ along many dimensions including firm size. The wage gap due to firm size of 35% is comparable to the gender wage gap of 36% for men over women and greater than the wage gap of 14% for whites over black employees. The size-wage premium is larger for men and varies across industries....