Permanent Income Shocks, Target Wealth, and the Wealth Gap
利用家庭对预防性目标财富的主观报告数据，检验缓冲库存模型的关键预测：永久收入变动会导致目标财富同比例调整，且实际财富向目标调整的速度与模型模拟一致。
We test the key implication of the buffer-stock model, namely that any revision in permanent income leads to a proportionate revision in target wealth. We use panel data on the amount of wealth that people think they must hold for precautionary purposes. Using the covariance restrictions that the model imposes on the joint behavior of income and target wealth, we find that households indeed revise, approximately one for one, their target wealth in response to permanent income shocks. The speed of adjustment of actual wealth to target wealth is similar to that obtained in simulations of a buffer-stock model.