We develop a multi-sector model of R&D-driven endogenous growth that merges the expanding-variety with the quality-ladders mechanism. The mechanism of expanding variety provides the flow of new firms (new product lines), whilst the mechanism of quality ladders provides the accumulation of...

This paper builds an endogenous growth model of directed technical change with vertical and horizontal R&D and scale effects at the industry level to study an analytical mechanism that is consistent with the observed cross-country pattern in the skill structure, the technology structure and...

This paper develops a tournament model of horizontal and vertical R&D under a lab-equipment specification. A key feature is that the overall growth rate is endogenous, as the splitting of the growth rate between the intensive and the extensive margin is itself endogenous. This setup gives rise...