Replication of two recent studies of growth determinants shows that results are sensitive to the choice of data from which growth rates are calculated, especially with respect to whether economic convergence has occurred. Previous warnings against using data that has been adjusted to increase...

Existing estimates of the annual unemployment rate from 1870 to 1913 were constructed by the Board of Trade, initially in 1888, and updated thereafter. This is still the series which is widely used and cited. It is based on records of the number unemployed in various trade unions and it has a...

The intellectual breakthrough contributed by the new growth theory was the recognition that investments in knowledge and human capital endogenously generate economic growth through the spillover of knowledge. Endogenous growth theory does not explain how or why spillovers occur. The missing link...

This paper studies the diffusion of a new technology that is brought to market while its potential is still uncertain. We consider a dynamic game in which firms improve both a new and a rival old technology while learning about the relative potential of both technologies. We use the model to...

This paper is a study of licensing in a patent thicket. In a patent thicket licensing allows firms to avoid hold-up. It will have different effects on firms' R&D incentives depending on whether firms license existing or future patents. Building on a model of a patent portfolio race, firms'...