Martin Gervais

Optimal Taxation in Life-Cycle Economies

We use a very standard life-cycle growth model, in which individuals have a labor-leisure choice in each period of their lives, to prove that an optimizing government will almost always find it optimal to tax or subsidize interest income. The intuition for our result is straightforward. In a life-cycle model the individual’s optimal consumption-work plan is almost never constant and an optimizing government almost always taxes consumption goods and labor earnings at different rates over an individual’s lifetime. One way to achieve this goal is to use capital and labor income taxes that vary with age. If tax rates cannot be conditioned on age, a non-zero tax on capital income is also optimal, as it can (imperfectly) mimic age-conditioned consumption and labor income tax rates.

Housing taxation and capital accumulation

This paper studies the impact of the preferential tax treatment of housing capital in a model economy that includes the main housing tax provisions currently in place in the U.S. and a minimum downpayment requirement upon purchasing non-divisible houses. Distortions arise because the tax code makes the return on housing capital larger than that on business capital. The wedge between the two rates of return emanates from the failure to tax imputed rents and is amplified by the presence of mortgage interest deductibility. Simulations show that either taxing imputed rents or eliminating mortgage interest deductibility substantially increases welfare. Moreover, welfare gains accrue to individuals at every income level and distributional effects are much smaller than conventionally believed.

Who Cares about Mortgage Interest Deductibility

We use the US Survey of Consumer Finances to measure the change in federal tax liability that would result should mortgage interest no longer be deductible from taxable income. We argue that the elimination of this housing tax provision would lead households to reshuffle their balance sheet, thereby lowering the amount of interest income taxes collected. We find that the cost of this tax provision is between 36 and 66 percent of the estimates produced by the US Office of Management and Budget, depending on the types of assets one assumes would be used to lower mortgage debt following the removal of the provision. Furthermore, since mostly rich households would be in a position to reshuffle their balance sheet following such a change in tax policy, the distributional effects of this program are much smaller than conventionally believed. While the focus of this paper is on the elimination of mortage interest deductibility in the US, the results of this study shed some light on the impact and distributional consequences to expect should mortgage interest deductibility be introduced in Canada.

First-Time Home Buyers and Residential Investment Volatility

Like other macroeconomic variables, residential investment has become much less volatile since the mid-1980s (recent experience notwithstanding.) This paper explores the role of structural change in this decline. Since the early 1980s there have been many changes in the underlying structure of the economy, including those in the mortgage market which have made it easier to acquire a home. We examine how these changes affect residential investment volatility in a life-cycle model consistent with micro evidence on housing choices. We find that a decline in the rate of household formation, increased delay in marriage, and an increase in the cross-sectional variance of earnings drive the decline in volatility. Our findings provide support for the view that the “Great Moderation” in aggregate fluctuations is not just due to smaller aggregate shocks, but is driven at least in part by structural change.

Uncertainty and the Specificity of Human Capital

This paper studies the choice between general and specific human capital. A trade-off arises because general human capital, while less productive, can easily be reallocated across firms. Accordingly, the fraction of individuals with specific human capital depends on the amount of uncertainty in the economy. Our model implies that while economies with more specific human capital tend to be more productive, they also tend to be more vulnerable to turbulence. As such, our theory sheds some light on the experience of Japan, where human capital is notoriously specific: while Japan benefited from this predominately specific labor force in tranquil times, this specificity may also have been at the heart of its prolonged stagnation.