Pedro Mazeda Gil

Growth and Firm Dynamics with Horizontal and Vertical R&D

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 to strong inter-R&D composition effects, while making economic growth and firm dynamics closely related, both along the balanced-growth path and transition. The model hence offers a (qualitative) explanation for the negative or insignificant empirical correlation between aggregate R&D intensity and both firm size and economic growth, a well-known puzzle in the growth literature.

Technological-Knowledge Dynamics in Lab-Equipment Models of Quality Ladders

The Perpetual Inventory Model (PIM) assumes that, in each period, an arbitrary constant fraction of technological-knowledge stock is lost. We give a theoretical background to the PIM by showing that the technological-knowledge accumulation follows a dynamic process with an endogenous depreciation rate, which remains stable in steady state.

A NOTE ON SKILL-STRUCTURE SHOCKS, THE SHARE OF THE HIGH-TECH SECTOR, AND ECONOMIC GROWTH DYNAMICS

By means of an endogenous growth model of directed technical change with vertical and horizontal R&D, we study a transitional-dynamics mechanism that is consistent with the changes in the share of the high- versus the low-tech sectors found in recent European data. Under the hypothesis of a positive shock in the proportion of high-skilled labour, the technological-knowledge bias channel leads to nonbalanced sectoral growth with a noticeable shift of resources across sectors. A simple calibration exercise suggests that, under prevailing market-scale effects, the model is able to account for up to 50 to 100 percent of the increase in the share of the high-tech sector observed in the data from 1995 to 2007. However, the model predicts that the dynamics of the share of the high-tech sector has no significant impact on the economic growth rate.