Simplified estimation method and cross-national comparison of lifespan distribution of durable goods

建立了一种估算耐用品寿命分布的简化方法。该方法将寿命分布的形状参数视为一个常数值，而不考虑国家和时间，只从在用产品总数和销售数据中估计寿命分布。利用所建立的方法，对20多个国家乘用车的年平均寿命进行了估计，并讨论了其差异和时间序列变化。

A simplified method for estimating lifespan distribution of durable goods was established. The method can estimate lifespan distribution only from total number of in-use products and sales data by regarding the shape parameter of the distribution as a constant value regardless of country and time period. By using the established method, average lifespan of passenger cars in over 20 countries was estimated for each year, and the differences and the time-series variations were discussed.