Constructing the true cost of living index from the Engel curves of the PIGLOG model
研究Tornqvist指数的性质，展示如何从简单的恩格尔曲线系统构建真实生活成本指数，从而估计固定权重指数中的替代偏差，并分解通货膨胀对不同支出水平家庭的影响。
Abstract This paper investigates the properties of the Tornqvist index and shows how this can be used to construct a true cost of living index from a simple system of Engel curves. This allows the substitution bias inherent in a fixed weight index to be estimated using the maximum degree of commodity disaggregation available in the data. Furthermore the proposed index can be decomposed to show the impact of inflation on households with different expenditure levels and household chararacteristics. An empirical application of the method is given, using data on UK food expenditures.