I evaluate the impact of the UK Working Time Regulations 1998, which introduced mandatory paid holiday entitlement. The regulation gave (nearly) all workers the right to a minimum of 4 weeks of paid holiday per a year. With constant weekly pay this change amounts effectively to an increase in...

The Wong-Viner Envelope Theorem on the equality of long-run and short-run marginal costs (LRMC and SRMC) is reformulated for convex but generally nondifferentiable cost functions. The marginal cost can be formalized as the multi-valued subdifferential a.k.a. the subgradient set but, in itself,...

This is a new formal framework for the theory of competitive equilibrium and its applications. Our “short-run approach” means the calculation of long-run producer optima and general equilibria from the short-run solutions to the producer’s profit maximization programme and its dual. The...