Induced Innovation, Evolutionary Theory and Path Dependence: Sources of Technical Change
回顾了1960至1980年代关于技术变革源泉的三种主要理论模型（诱导创新、演化模型和路径依赖模型），指出它们各自面临瓶颈，并呼吁构建一个更综合的理论框架。
The 1960s to the 1980s were very productive of new theory and empirical insights into the sources of technical change. In the 1960s and 1970s major attention focused on the implications of changes in demand and relative factor prices on the rate and direction of technical change. In the late 1970s and early 1980s attention shifted to evolutionary models inspired by a revival of interest in Schumpeter's insights into the process of economic development. Since the early 1980s these have been complemented by the development of historically grounded ‘path dependent’ models of technical change. Each of these models has contributed substantial insight into the sources of technical change. This paper was motivated by a perception that each of the three research agendas is approaching a dead end.1 The three models – induced, evolutionary, and path dependent – represent elements of a more general theory that has not yet been invented (Ruttan, 1996a). In a closing comment I suggest some steps toward the development of a more general theory of the sources of technical change.