I. IntroductionLow rates of saving in the United States have created widespread concern over investment, growth, the balance of payments, and the financial security of individual households. These concerns have prompted a variety of proposal designed to stimulate saving through tax incentives, ranging from narrowly focused tax-favored savings accounts, to broad-based consumption taxation. Before attempting to weigh the advantages and disadvantages of these proposals, it is important to marshall the available evidence, and review the lessons that economists have learned about the relation (or relations) between tax incentives and personal saving.This paper undertakes a review of the existing academic work in this area. It attempts both to evaluate the evidence, and to identify the important open questions. Although it does not include a full evaluation of any particular saving incentive proposal, it does identify relevant implications.The central conclusions of this review are as follows. First, the traditional life cycle hypothesis has had an excessive influence on the design and conceptualization of empirical investigations concerning the relation between taxation and saving. While other behavioral hypotheses are mentioned in the literature with increasing frequency, this usually occurs in the course of explaining an anomalous result, rather than at the stage of designing an empirical strategy, or even at the stage of evaluating results that do not appear to be anomalous from a lifecycle perspective. In part, this is no doubt attributable to the absence of sufficiently welldeveloped organizing principles for a compelling behavioral alternative. But even in the absence of an intellectually satisfying alternative, it is important to be aware of the potential for reaching misleading conclusions by imposing potentially false structure on the data. Second, there is little reason to believe that households increase their saving significantly in response to a generic increase in the after-tax rate of return. Since the evidence is quite poor, there is still considerable uncertainty on this point. However, it is difficult to identify any robust empirical pattern that is suggestive of a high elasticity., Third, the literature on the relation between Individual Retirement Accounts (IRAs) and personal saving is inconclusive. Studies that point to a large effect on personal saving contain identifiable biases that overstate this effect. Likewise, studies that find little or no effect on personal saving contain identifiable biases that understate the effect. Due to the nature of the IRA program and the characteristics of the available data, reliable estimation of the effect on personal saving may well be impossible. However, the IRA experience does provide reasonably strong evidence that households' responses to narrowly-focused tax incentives are governed, at least in part, by forces that are not considered in the traditional life cycle framework.Fourth, the available evidence on 401(k)s allows one to conclude with moderate ...