Assessing the Productivity of Information Technology Equipment in U.S. Manufacturing Industries
基于1952-1991年美国两位数制造业行业数据，评估信息技术设备投资对成本降低的影响，发现1980年代后期存在过度投资，但非耐用品行业的高投资因回报和价格下降而合理，且高技术资本扩张增加了对多数投入的需求但节省了材料。
We assess the cost-reducing impacts of increasing stocks of "high-tech" equipment (O capital). Our empirical analysis is based on a dynamic production theory model and annual data for two-digit U.S. manufacturing industries (1952-1991). We find evidence of overinvestment in O capital in the mid to late 1980s, following a period of strong investment incentives in the late 1970s. By the end of the 1980s, however, the returns to investment and falling prices for O capital more than justified the high investment levels in nondurable-goods industries, and the benefit-cost ratio was also increasing for durable-goods industries. The underlying substitution patterns suggest that high-tech capital expansion increases demand for most capital and noncapital inputs overall, but saves on materials inputs. In durables industries, however, both energy and "other" capital appear somewhat substitutable with O capital, and in nondurables industries increasing high-tech intensity may be a factor underlying stagnating labor demand. © 1997 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology