Weak Separability and the Estimation of Elasticities in Multistage Demand Systems
回顾了多阶段预算近似合理的必要条件，讨论了弱可分性和价格指数随效用水平低变动的假设，推导了不同预算层级间支出和价格弹性的简单关系，并应用于瑞典食品消费的三阶段模型，发现仅分析最后阶段会导致显著误差。
Abstract The necessary conditions for multistage budgeting to be at least approximately justified are reviewed, and the plausibility of these assumptions (i.e., weak separability and low variability of price indices with utility level) are discussed. Using no further assumptions, simple relationships between expenditure and price elasticities in different budgeting levels are derived. These results are applied to a three‐stage model for Swedish food consumption, and it is shown that the assumptions are not inappropriate. Restricting the analysis to the last stage of a multistage budgeting process is also shown to lead to considerable errors, which could well have policy consequences.