Present Bias and Collective Dynamic Choice in the Lab
研究时间贴现个体如何集体决定共同消费流，发现时间偏好异质性会导致现时偏向，实验室中多数社会规划者表现出现时偏向，少数为时间一致。
We study collective decisions by time-discounting individuals choosing a common consumption stream. We show that with any heterogeneity in time preferences, utilitarian aggregation necessitates a present bias. In lab experiments three quarters of “social planners” exhibited present biases, and less than two percent were time consistent. Roughly a third of subjects acted as if they were pure utilitarians, and the rest chose as if they also had varying degrees of distributional concerns.