Problems in the Measurement of Prices and Productivity

过去25年美国劳动生产率的缓慢增长，与此前半个世纪的快速增长形成鲜明对比，构成了人们经常讨论的“生产率放缓”。迄今为止，任何基于单一原因的理论都无法解释经济放缓，比如能源价格、资本投资、基础设施投资、政府监管和教育考试成绩。最近，人们的注意力集中在对价格变化的错误衡量可能部分或很大程度上解释了经济放缓的可能性。据推测，产出增长现在比以前更难衡量，部分原因是计算机正在产生无法衡量的无形利益，结果是，与经济放缓之前相比，近几十年来，通胀被夸大了，生产率增长被低估了。这个项目的新颖之处在于，通过探索通胀在经济放缓之前的前几十年可能被低估（或被大大低估）的可能性，将假定的偏差方向颠倒过来。这种可能性迄今尚未得到系统的研究，它意味着生产率增长在黄金时代（跨越1915年至1972年期间）可能被夸大了，当时可测量的生产率增长迅速。如果这一假设得到这项研究的支持，它将至少在一定程度上解释经济放缓，因为它表明，近几十年的生产率增长与黄金时代相比，并不像之前认为的那样糟糕。为该项目制定的一套研究标准导致选择住房服务（租金和房屋所有权）作为研究的中心焦点，其目的是开发从第一次世界大战至今的整个时期住房价格和质量变化的新指数。该项目揭示了几个数据来源，这些数据表明，住宅租金的官方CPI（国民收入账户中住房拥有率下降的基础）可能大大低估了经质量调整的租金的通货膨胀，特别是在1930年至1970年之间。住宅住房质量研究的一个有用的副产品将是提供新的信息，以重新评估过去三十年来建筑业生产率负增长的难题。住房价格的研究将使用几种技术来汇编关于住房质量和价格的数据。一些鲜为人知的研究涵盖了1930 - 1970年期间，可以向前和向后扩展，使用来自行业来源和早期消费者支出调查的租赁公寓和房屋的质量特征数据，以及来自住房普查和当前住房报告的最新政府数据。将使用方差分析或享乐回归方法对数据进行分析，并将新的估计值与先前研究的系数相结合。该研究还提供了证据，表明CPI可能低估了服装的历史通胀率，而服装是消费者支出的另一个重要组成部分。对同一数据源中匹配模型指数的平均支付价格的比较表明，与匹配模型指数或CPI相比，服装通货膨胀率可能要快得多。如果这种可能性通过长期历史间隔内服装价格的享乐回归研究得到验证，它将增加住房价格在改变美国产出和生产率增长的标准历史数据方面的研究，潜在地降低了第一次世界大战至1970年之间的生产率增长，从而解释了1970年后生产率增长放缓的部分原因。服装的研究也可能意味着其他产品之前匹配的模型指数，以及基于模型变化之间的链接的许多CPI组件，可能需要重新检查。

The slow rate of growth in U. S. labor productivity in the last 25 years, in contrast to much faster growth in the previous half century, constitutes the much discussed `productivity slowdown.` Thus far the slowdown has eluded explanation by any theory based on a single cause, such as the behavior of energy prices, capital investment, infrastructure investment, government regulation, and educational test scores. More recently attention has focussed on the possibility that mis-measurement of price changes may partly or largely explain the slowdown. It has been conjectured that output growth is now more difficult to measure than previously, partly because computers are producing unmeasured intangible benefits, and as a result that inflation has been overstated and productivity growth understated more in recent decades than prior to the slowdown. The novelty in this project is to turn the presumed direction of bias upside down by exploring the possibility that inflation may have been understated (or overstated by substantially less) in earlier decades prior to the slowdown. This possibility, which has not heretofore been systematically investigated, implies that productivity growth may have been overstated in the golden era (spanning the period between 1915 and 1972) when measured productivity growth was rapid. If this hypothesis is supported by this research, it would explain the slowdown at least in part by showing that productivity growth in recent decades does not compare so badly with that in the golden era as has previously been thought. A set of research criteria developed for this project leads to the choice of shelter services (both rent and homeownership) as the central focus of the research, the aim of which is to develop new indexes of price and quality change for shelter over the full period from World War I to date. The project uncovers several sources of data suggesting that the official CPI for residential rent, which is the basis for the deflation of home ownership in the national income accounts, may substantially understate inflation in quality adjusted rents, particularly between 1930 and 1970. A useful byproduct of the research on the quality of residential shelter will be to provide new information to reassess the puzzle of negative productivity growth in the construction industry over the past three decades. The study of shelter prices will use several techniques to compile data on housing quality and prices. Several little-known studies covering the 1930 1970 period can be extended forward and backwards, using data on quality characteristics of rental apartments and houses from industry sources and consumer expenditure surveys for the earlier years, and existing government data from the Census of Housing and Current Housing Reports for the more recent period. Data will be analyzed using the analysis of variance or the hedonic regression approach, combining new estimates with coefficients from previous studies. The research also provides evidence that the CPI may understate the historic inflation rate for apparel, another important component of consumer expenditure. Comparisons of average prices paid with matched model indexes from the same data source suggest the possibility of a much more rapid rate of apparel inflation than in the matched model indexes or in the CPI. If this possibility is validated by a hedonic regression study of apparel prices over long historical intervals, it would augment the research on shelter prices in altering the standard historical data on U. S. output and productivity growth, potentially reducing the growth of productivity between World War I and 1970 and thus explaining part of the post 1970 productivity growth slowdown. The apparel research may also imply that previous matched model indexes for other products, as well as the many CPI components based on linking across model changes, may need to be reexamined.