Do households use savings to buffer against income fluctuations? Despite its common use to understand household savings decisions, the evidence for the buffer-stock model is surprisingly weak and inconsistent. This paper develops new testable implications based on a property of the model that the assets that households target for precautionary reasons should encapsulate all preferences and risks and the target should scale one for one with permanent income. I test these implications using the Survey of Consumer Finances in the United States. Those with incomes over $60,000 fit the model predictions very well, but below $60,000 households become increasingly precautionary. Income uncertainty is unrelated to the level of precaution. Moreover, households hold substantially weaker precautionary tendencies than standard models with yearly income shocks predict. Instead I propose and estimate a model of monthly disposable income shocks and a minimum subsistence level that can accommodate these findings.
