This paper examines Ricardian equivalence in a world in which taxes are not lump sum, but are levied on risky labor income. It shows that the marginal propensity to consume out of a tax cut, coupled with a future income tax increase, can be substantial under plausible assumptions. Indeed, the MPC out of a tax cut can be closer to the Keynesian value that ignores the future tax liabilities than to the Ricardian value that treats future taxes as if they were lump sum.

This paper argues that a life cycle model can replicate observed patterns in household wealth accumulation after counting explicitly for precautionary saving and asset-based, means-tested social insurance. The authors demonstrate that social insurance programs with means tests based on assets discourage saving by households with low expected lifetime income. In addition, they evaluate the model using a dynamic programming model. Assuming common preference parameters across lifetime income groups, the authors are able to replicate the empirical pattern that low-income households are more likely than high-income households to hold virtually no wealth.

The Importance of Bequests and Life-Cycle Saving in Capital Accumulation: A New Answer by Karen E. Dynan, Jonathan Skinner and Stephen P. Zeldes. Published in volume 92, issue 2, pages 274-278 of American Economic Review, May 2002

The question of whether higherlifetime income households save a larger fraction of their income was the subject of much debate in the 1950s and 1960s, and while not resolved, it remains central to the evaluation of tax and macroeconomic policies. We resolve this long-standing question using new empirical methods applied to the Panel Study of Income Dynamics, the Survey of Consumer Finances, and the Consumer Expenditure Survey. We find a strong positive relationship between saving rates and lifetime income and a weaker but still positive relationship between the marginal propensity to save and lifetime income. There is little support for theories that seek to explain these positive correlations by relying solely on time preference rates, nonhomothetic preferences, or variations in Social Security benefits. There is more support for models emphasizing uncertainty with respect to income and health expenses, bequest motives, and asset-based means testing or behavioral factors causing minimal saving rates among low-income households.