Viscous Demand

In many markets, demand adjusts slowly to changes in prices, i.e., demand is "viscous". This viscosity gives each firm some monopoly power, since it can raise its price above that of its competitors without immediately losing all of its customers. The resulting equilibrium pricing behavior and market outcomes can differ significantly from what one would predict in the absence of demand viscosity. In particular, the model explains the importance of market share as an investment, as well as "kinked demand curves". It also explains how apparently "competitive" pricing behavior can lead to outcomes that mimic those of collusion.