Errors of Measurement in Output Deflators
研究生产者价格指数（PPI）与普查单位价值比这两种长期价格变化估计中的测量误差，发现PPI更可靠，并评估质量变化对价格和生产率测量的影响。
Abstract We investigate the incidence of measurement errors in two independent estimates of long-term price change, the producer price index (PPI) and the U.S. Bureau of the Census's unit value relative, within the framework of multiple-indicators models of price measurement. Our estimates of the measurement-error variances suggest that the PPI is a far more reliable indicator of long-term price change. We also assess the importance of the problem posed by quality change for price and productivity measurement. Apparently, less than half of quality change is adjusted for in the PPI, so conventional productivity statistics underestimate "quality-adjusted" productivity growth by 34%. KEY WORDS: Data qualityPrice indexesProduct quality changeProductivityReliability