Endogenous Technological Change Daron Acemoglu 经济增长导论课件.pdfVIP

14.452 Economic Growth: Lectures 9 and 10, Endogenous Technological Change Daron Acemoglu MIT November 24 and December 1, 2009. November 24 and December 1, 2009. 1 Daron Acemoglu (MIT) Economic Growth Lectures 9 and 10 / 60 Endogenous Technological Change Expanding Variety Models Introduction The key to understanding technology is that RD and technology adoption are purposeful activities. This lecture, focus on technological change and RD. The simplest models of endogenous technological change are those in which RD expands the variety of inputs or machines used in production (Romer, 1990). Models with expanding input varieties: research will lead to the creation of new varieties of inputs (machines) and a greater variety of inputs will increase the ìdivision of laborî process innovation. Alternative: product innovation (Grossman and Helpman (1991a,b)): invention of new goods, because of love-for-variety, ìrealî incomes increase November 24 and December 1, 2009. 2 Daron Acemoglu (MIT) Economic Growth Lectures 9 and 10 / 60 Endogenous Technological Change Expanding Variety Models Key Insights Innovation as generating new blueprints or ideas for production. Three important features (Romer): 1 Ideas and technologies nonrivaló many Örms can beneÖt from the same idea. 2 Increasing returns to scaleó constant returns to scale to capital, labor, material etc. and then ideas and blueprints are a