Dynamic Price Competition with Price Adjustment Costs and Product Differentiation

We study a discrete time dynamic game of price competition with spatially differentiated products and price adjustment costs. We characterise the Markov perfect and the open-loop equilibrium of our game. We find that in the steady state Markov perfect equilibrium, given the presence of adjustment costs, equilibrium prices are always higher than prices at the repeated static Nash solution, even though, adjustment costs are not paid in steady state. This is due to intertemporal strategic complementarity in the strategies of the firms and from the fact that the cost of adjusting prices adds credibility to high price equilibrium strategies. On the other hand, the stationary open-loop equilibrium coincides always with the static solution. Furthermore, in contrast to continuous time games, we show that the stationary Markov perfect equilibrium converges to the static Nash equilibrium when adjustment costs tend to zero. Moreover, we obtain the same convergence result when adjustment costs tend to infinity.Price adjustment costs, Difference game, Markov perfect equilibrium, Open-loop equilibrium

Partial Multihoming in Two-sided Markets

In this paper we explore the possibility of "partial-multihoming" in a two-sided market where a subset of agents, on one or both side(s), may multihome in equilibrium. We consider a model in which platforms are spatially differentiated and on each side of the market there are two type of agents, low type and high type agents, that differ only by their preferences over the network benefits. We derive under which conditions of network preferences, an equilibrium with partial multihoming on both sides exists. We show that for such an equilibrium to exist, the network benefits of high type agents must be sufficiently higher than transportation costs. Furthermore, the proportions of agents who multihome on both sides must be sufficiently small. Finally, we show that independently of the degree of multihoming on the other side of the market, agents in each group face higher prices when there is partial multihoming on their side than when there is singlehoming.Two-sided markets, network externalities, heterogeneous agents.

Dynamic price competition with price adjustment costs and product differentiation

We study a discrete time dynamic game of price competition with spatially differentiated products and price adjustment costs. We characterise the Markov perfect and the open-loop equilibrium of our game. We find that in the steady state Markov perfect equilibrium, given the presence of adjustment costs, equilibrium prices are always higher than prices at the repeated static Nash solution, even though, adjustment costs are not paid in steady state.This is due to intertemporal strategic complementarity in the strategies of the firms and from the fact that the cost of adjusting prices adds credibility to high price equilibrium strategies. On the other hand, the stationary open-loop equilibrium coincides always with the static solution. Furthermore, in contrast to continuous time games, we show that the stationary Markov perfect equilibrium converges to the static Nash equilibrium when adjustment costs tend to zero. Moreover, we obtain the same convergence result when adjustment costs tend to infinity

Dynamic Price Competition with Price Adjustment Costs and Product Differentiation

We study a discrete time dynamic game of price competition with spatially di¤erentiated products and price adjustment costs. We characterise the Markov perfect and the open-loop equilibrium of our game. We …nd that in the steady state Markov perfect equilibrium, given the presence of adjustment costs, equilibrium prices are always higher than prices at the repeated static Nash solution, even though, adjustment costs are not paid in steady state. This is due to intertemporal strategic complementarity in the strategies of the …rms and from the fact that the cost of adjusting prices adds credibility to high price equilibrium strategies. On the other hand, the stationary open-loop equilibrium coincides always with the static solution. Furthermore, in contrast to continuous time games, we show that the stationary Markov perfect equilibrium converges to the static Nash equilibrium when adjustment costs tend to zero. Moreover, we obtain the same convergence result when adjustment costs tend to in…nity

1 Estimating Union Wage E¤ects in Great Britain During 1991-2003 1;2

Using a dynamic model of unionism and wage determination we …nd that the unobserved factors that in‡uence union membership also a¤ect wages. The estimates suggest that UK trade unions still play a non-negligible, albeit diminishing, role in wage formation. It appears that the greater impact of unobservables in determining individual union propensity concerning the second period under analysis, versus past unionisation experience, implies that those remaining in unions during (1997-2002) gain most from their sorting decision. The signi…cant contribution of unobserved heterogeneity renders the total union wage di¤erential highly variable across individuals. The endogeneity correction procedure employed yields a discernible pattern of the estimated union wage e¤ect relative to OLS and Fixed e¤ects. This is in line with Robinson (1989a) and Vella and Verbeek (1998) and refutes the pessimistic conclusions reached by Freeman and Medo¤ (1982) and Lewis (1986) that endogeneity correction methodologies do not contribute to our understanding of the union wage e¤ect puzzle