This paper explores the economic factors which determine the variation of research effort across firms. The intra-industry coefficient of variation of research intensity is much larger than those of traditional factors. We show that this important fact is consistent with the theoretical argument...

This paper points out the conceptual distinction between the rates of decay in the physical productivity of traditional capital goods and that of the appropriate revenues accruing to knowledge-producing activities, and notes that it is the latter parameter which is required in any study which...

This paper is concerned with developing a semiparametric panel model to explain the trend in UK temperatures and other weather outcomes over the last century. We work with the monthly averaged maximum and minimum temperatures observed at the twenty six Meteorological Office stations. The data is...