Does Repeated Measurement Improve Income Data Quality?
利用面板调查设计中的自然实验，发现第二次受访比第一次受访的平均月收入高出8%，其中三分之一由依赖式访谈（一种回忆辅助工具）解释，其余归因于受访者行为变化（面板条件作用）。
Abstract This paper exploits a natural experiment created by a survey design to show that the quality of income data systematically changes across waves of a panel. We estimate that the effect of being interviewed for a second time, relative to the first, is to increase mean monthly income by 8%. Dependent interviewing – a recall device commonly used in panel surveys – explains one third of the observed increase. The remaining share is attributed to changes in respondent behaviour (panel conditioning). We review the evidence for and against a reporting improvement vs. a behavioural response by survey participants.