For many kinds of capital, depreciation rates change systematically with the age of the capital. Consider an example that captures essential aspects of human capital, both regarding its accumulation and its depreciation: a worker obtains knowledge in period 0, then uses this knowledge in...

This paper considers a three-overlapping-generations model of endogenous growth wherein human capital is the engine of growth. It first contrasts the laissez-faire and the optimal solutions. Three possible accumulation regimes are distinguished. Then it discusses a standard set of tax-transfer...

In this paper we explore the consequences for optimality of a social planner adopting two different welfare criteria. The framework of analysis is an OLG model with physical and human capital. We first show that, when the SWF is a discounted sum of individual utilities defined over consumption...

This paper offers a comprehensive study on transitional dynamics within R&D-based models of endogenous growth. There are two main motivations. First, the complete dynamic system for the market solution is derived in general form. Second, using this dynamic system as a unifying framework the...

An 'incentive subsidy' policy for subsidizing private R & D is proposed that can be more efficient, from a social point of view, than subsidy policies in common use such as a 'normal' subsidy policy (fixed amount granted at project start), and conditional loans (loan is repaid only if project is...

Tax incentives for innovation, including in particular the incentives for R&D investments, are universally used policy tools. Their availability and generosity have significantly increased over the past three decades. The observed proliferation of R&D tax incentives raises the question of the...