Using US firm level panel data we simultaneously assess the contributions to productivity of three potential sources of research and development spillovers: geographic, technological, and product market ("horizontal"). To do so, we construct new measures of geographic proximity based on the...

We review the empirical literature that extends and tests the Hotelling model of the optimal depletion of an exhaustible resource. The theory is briefly described to set the stage for the review of empirical tests and applications. Those tests can be roughly divided into two broad...

[eng] Many commodity markets satisfy the assumptions that underlie the Cournot model. These markets, however, have a feature that is not considered in that model - producers and consumers can enter into contracts for forward transactions. We consider the implications of forward trading for...

We simultaneously assess the contributions to productivity of three sources of research and development spillovers: geographic, technology and product–market proximity. To do this, we construct a new measure of geographic proximity that is based on the distribution of a firm’s inventor...

The purpose of this paper is threefold. First, we give an overview of the general direction the spatial econometrics literature has taken without attempting to provide a representative survey of all interesting work that has appeared. Second, we identify a number of problems in spatial...