We show a causal impact of immigration on innovation and dynamism in US counties. To identify the causal impact of immigration, we use 130 years of detailed data on migrations from foreign countries to US counties to isolate quasi-random variation in the ancestry composition of US counties that...

In this chapter we argue that the endogenous growth model with quality-improving innovations provides a framework for analyzing the determinants of long-run growth and convergence that is versatile, simple and empirically useful. Versatile, as the same framework can be used to analyze how growth...

We construct a tractable general equilibrium model of cumulative innovation and growth, in which new ideas strictly improve upon frontier technologies, and productivity improvements are drawn in a stochastic manner. The presence of positive knowledge spillovers implies that the decentralized...

We analyze recent contributions to growth theory based on the model of expanding variety of Romer [Romer, P. (1990). “Endogenous technological change”. Journal of Political Economy 98, 71–102]. In the first part, we present different versions of the benchmark linear model with imperfect...

We analyze recent contributions to growth theory based on the model of expanding variety of Romer (1990). In the first part, we present different versions of the benchmark linear model with imperfect competition. These include the “labequipment” model, labor-for-intermediates” and...

The literature on economic growth has identified knowledge expansion as a key propellant. Early research derived this conclusion from the residual that remained after the growth contributions from capital and labour had been accounted for. Later modifications expanded the concept of fixed...

We study how exploration versus exploitation innovations impact economic growth through a tractable endogenous growth framework that contains multiple innovation sizes, multi-product firms, and entry/exit. Firms invest in exploration R&D to acquire new product lines and exploitation R&D to...

We study how exploration versus exploitation innovations impact economic growth through a tractable endogenous growth framework that contains multiple innovation sizes, multiproduct firms, and entry/exit. Firms invest in exploration R&D to acquire new product lines and exploitation R&D to...

This paper studies the effects of public research (publications) and innovation output (patents) on national economic growth with the help of a GMM panel regression including 114 countries. Effects on productivity growth and capital and labor inputs are distinguished. Furthermore, different time...

We study an endogenous growth model where a profit-motivated R and D sector coexists with the introduction of free blueprints invented by philanthropists. These goods are priced at marginal cost, contrary to proprietary ones which are produced by a monopoly owned by the inventor. We show that...