This note studies a general nonstationary infinite-horizon optimization problem in discrete time. We allow the state space in each period to be an arbitrary set, and the return function in each period to be unbounded. We do not require discounting, and do not require the constraint...

This paper establishes (i) an extension of Michel's (1990, Theorem 1) necessity result to an abstract reduced-form model, (ii) a generalization of the results of Weitzman (1973) and Ekeland and Scheinkman (1986), and (iii) a new result that is useful particularly in the case of homogeneous...

This paper establishes (i) an extension of Michel's (1990, Theorem 1) necessity result to an abstract reduced-form model, (ii) a generalization of the results of Weitzman (1973) and Ekeland and Scheinkman (1986), and (iii) a new result that is useful particularly in the case of homogeneous...

This paper strengthens the Hopenhayn and Prescott stability theorem for monotone economies. We extend the theorem to a larger class of applications, and develop new perspectives on the nature and causes of stability and instability. In addition, we show that models satisfying the...

Common wisdom suggests that entry reduces profits of the incumbentfirms. On the contrary, we show that if the incumbents differ in marginal costs and theentrants behave like Stackelberg followers, entry may benefit the incumbents who arerelatively cost efficient while it always hurts the cost...