Cartelization under present bias and imperfect public signals

This paper explores the impact of present bias on trigger pricing strategies that are used to support a cartel in a market where firms can only observe a noisy price signal. The present bias of firm management is modelled by using quasi-hyperbolic discounting that the discount factor between the present and next period is βδ, and between any two adjacent periods later it is δ. We demonstrate that there is a threshold value β̲(δ), which is decreasing in δ. For β≥β̲(δ), we show that there exists a Nash reversion trigger strategy for the cartel, featuring lower prices, higher outputs and longer periodic price wars. As a consequence, the trigger price, which is shown to be proportional to the cartel price, is always lower than that in the Green-Porter model.