The Diffusion of Information Technology Capital: An Industry Analysis

信息技术(IT)资本目前占美国总股本的7%，在资本支出中所占份额迅速增长，使其成为近年来最重要的创新之一。令人惊讶的是，很少有理论或经验分析关注IT的扩散，特别是量化其增长。鉴于信息技术作为资本投入在每个经济部门的重要作用，分析这些增长趋势是很重要的。该项目从行业和总体经济两个层面研究了1972年至1987年期间对信息技术资本的需求。虽然许多文献提到IT的增长是在创新扩散和S.Curve行为的背景下进行的，但本项目认为，计算成本的下降将对扩散模式产生重大影响。研究人员开发了信息技术需求的经济模型，将这两个因素结合起来。模型还考察了其他因素的影响，包括劳动力成本和一般商业条件对IT需求的影响。模型的质量及其形式和参数是通过对行业和总体经济层面的信息技术存量和流量数据进行计量分析来确定的。本研究检验了创新扩散效应与价格效应在多大程度上可以解释IT存量的增长。首席调查员研究了总量和行业需求函数之间的关系，以及行业间的差异。

Information Technology (IT) capital currently represents 7% oftotal capital stock in the U.S. and accounts for a rapidlygrowing share of capital expenditures, making it one of the mostimportant innovations of recent times. Surprisingly, fewtheoretical or empirical analyses have focussed on the diffusionof IT and in particular, quantified its growth. Given thesignificant role of IT as a capital input in every sector of theeconomy, it is important to analyze these growth trends. This project studies the demand for IT capital for the period1972.1987 at both the industry and the aggregate economy levels. While much of the literature refers to the growth of IT in thecontext of the diffusion of innovation and S.curve behavior, itis argued in this project that the declining costs of computingwill have a significant impact on the pattern of diffusion. Theresearcher develops economic models of the demand for IT thatintegrate these two factors. The models also examine theinfluence of other factors, including the cost of labor andgeneral business conditions on the demand for IT. The quality ofthe models, and their form and parameters are determined throughan econometric analysis of data on the stocks and flows of IT atthe industry and aggregate economy levels. The research examinesthe extent to which the growth of IT stock can be explained bythe effects of the innovation diffusion versus the price effects. The Principal Investigator looks at the relationships between theaggregate and the industry demand functions as well as inter.industry differences.