Accounting for Price Changes: American Steel Rails, 1879-1910
构建了一个分解产品价格变动的框架，用于衡量非竞争性行业的生产率增长。通过分析1879-1910年美国钢轨价格历史，发现生产率增长持续到20世纪初，且钢铁行业的合谋使生产者以超额利润形式获得了生产率增长的收益。
A framework is developed for decomposing product price changes into changes in input prices, technical efficiency, and deviations of price from unit cost. This framework facilitates the measurement of productivity growth in noncompetitive industries. The history of American steel rail prices between 1879 and 1910 is analyzed, and it is concluded (in contrast with much recent work) that productivity growth remained rapid until the twentieth century and that the steel industry was sufficiently collusive so that the rail producers received the benefits of that productivity growth as excess profits.