In his 1987 entry on ‘Perfect Competition’ in The New Palgrave, the author reviewed the question of the perfectness of perfect competition, and gave four alternative formalisations rooted in the so-called Arrow-Debreu-Mckenzie model. That entry is now updated for the second edition to...

The Harris-Todaro hypothesis replaces the equality of wages by the equality of ‘expected’ wages as the basic equilibrium condition in a segmented but homogeneous labour market, and in so doing it generates an equilibrium level of urban unemployment when a mechanism for the determination of...