The author investigates the welfare cost of business cycles in an economy where households have heterogeneous trading technologies. In an economy with aggregate risk, the different portfolio choices induced by heterogeneous trading technologies lead to a larger consumption inequality in...

This paper studies the implications of financial market imperfections represented by a countercyclical external finance premium and the gradual recognition of changes in the drift of technology growth for the design of an interest rate rule. Asset price movements induced by changes in trend...

In a Cournot oligopoly set up with constant marginal cost and linear demand, innovation is rewarding. In this paper we work with a Cournot oligopoly framework with increasing marginal cost and linear demand and show that innovation may not be rewarding. We endogenize the success probability of...

We analyze a model of cost-reducing R&D and compatibility decisions by two platforms. After an exogenous improvement in the efficiency of R&D, each platform has a heightened incentive to make its software incompatible with the rival's hardware device to avoid being dominated in the hardware...

We study the gains from trade in an economy with oligopolistic competition, firm heterogeneity, and innovation. Oligopolistic competition together with free entry make markups responsive to firm productivity and trade costs. Lowering trade costs reduces markups on domestic sales but increases...

This paper explores a firm's incentive to technologically tie when Ramp;D is important and finds that technological tying increases innovation, which is an efficiency not considered in other tying models. Intuitively, technological tying protects the seller from aftermarket entry, ensuring that...

We study the gains from trade in a model with oligopolistic competition, heterogeneous firms and innovation, and provide a formula to decompose the mechanism. The new insight we provide is that market concentration can be a welfare-relevant feature of market power above and beyond markup...

This paper models the welfare consequences of social fragmentation arising from technological advance. We start from the premise that technological progress falls primarily on market-traded commodities rather than prosocial relationships, since the latter intrinsically require the expenditure of...