Trading gains: terms‐of‐trade and real‐exchange‐rate effects
研究了国家贸易收益的衡量方法，指出贸易收益由贸易条件效应和实际汇率效应两部分组成，而多数统计机构只计算前者，导致实际国内总收入（GDI）的估计存在概念缺陷，并提出了使用国内最终支出价格指数作为缩减指数的改进方案。
Abstract This paper considers alternative measures of a country's trading gains, i.e., the extra income that it earns (or loses) as the result of changes in the relative prices relevant for international trade, and which makes up the difference between real gross domestic product (GDP) and real gross domestic income (GDI). Looking at both the Laspeyres and the Törnqvist aggregation, we show that the trading gains really consist of two components, a terms‐of‐trade effect and a real‐exchange‐rate effect. Nearly all national statistical agencies, receiving no firm guidance from international organizations in this matter, merely consider the first effect, which suggests that the so‐called trading‐gain estimates they publish are incomplete and misnamed. Even more seriously, it implies that the corresponding measures of real GDI they derive are conceptually flawed. A straightforward way to circumvent these difficulties is to use the gross domestic final expenditure price index as deflator when computing real GDI and the trading gains. Some numerical estimates for Australia are provided as an illustration. The paper also identifies the underlying linear and Translog real GDI functions for which the Laspeyres and Törnqvist terms‐of‐trade and real‐exchange‐rate effects are exact.