The canonical approach to measuring private and social returns to R&D assumes diffusion through spillovers. We develop a general framework that allows R&D to diffuse through both spillovers and voluntary technology transfers. To operationalize the framework, we create a data set of interactions in the market for technology between publicly held US firms. We use changes in tax incentives for R&D to identify causal effects. Taking market channels into account decreases the observed difference between social and private returns to R&D as compared with the canonical approach. The analysis suggests significant gains from trade in markets for technology.

A sequential equilibrium model of private antitrust enforcement is presented. Consumers have incomplete information about cartel costs and cannot accurately estimate a priori the damage recovery from an antitrust action. Consumers are able to infer cartel costs from the equilibrium pricing strategy of firms. The universal divinity criterion is used to characterize the sequential equilibrium. It is shown that, for a sufficiently large damage multiple, antitrust enforcement effectively increases social welfare.