In the pure theory of foreign trade, offer curves are still a well-known textbook device for analyzing conflicting interests between countries engaged in foreign trade. In his early days Alfred Marshall suggested that this analytical device be used also for industrial disputes between workers'...

Keynes' concept of a Z_w-function relates the value of aggregate supply in wage units to employment. It aroused much controversy until the very recent past. A special bone of contention was the question of whether Keynes intended the Z_w-curve to be drawn as a 45° line. This note argues that the...