Measuring Peer Effects on Youth Smoking Behaviour

This paper examines the role of peer effects in teenagers' smoking behaviour in the U.S.A. I present a random utility model that incorporates complementarity between individual and peer smoking. A Markov process model of smoking interactions between individuals is presented. I estimate the structural parameters of the model using a steady-state distribution that is determined by the Markov process. The empirical results strongly support the presence of positive peer effects. Interestingly, peer interactions are found to be stronger within the same gender than across genders. The same result is found for race. Moreover, a multiplier effect is found.     

BAYESIAN ANALYSIS OF GENERALIZED AUTOREGRESSIVE CONDITIONAL HETEROSKEDASTICITY AND STOCHASTIC VOLATILITY: MODELING LEVERAGE,JUMPS AND HEAVY‐TAILS FOR FINANCIAL TIME SERIES*

This paper develops a Bayesian model comparison of two broad major classes of varying volatility model, the generalized autoregressive conditional heteroskedasticity and stochastic volatility models, on financial time series. The leverage effect, jumps and heavy‐tailed errors are incorporated into the two models. For estimation, the efficient Markov chain Monte Carlo methods are developed and the model comparisons are examined based on the marginal likelihood. The empirical analyses are illustrated using the daily return data of US stock indices, individual securities and exchange rates of UK sterling and Japanese yen against the US dollar. The estimation results indicate that the stochastic volatility model with leverage and Student‐t errors yield the best performance among the competing models.     

Constrained Inefficiency and Optimal Taxation with Uninsurable Risks

When individuals' labor and capital income are subject to uninsurable idiosyncratic risks, should capital and labor be taxed, and if so how? In a two‐period general equilibrium model with production, we derive a decomposition formula of the welfare effects of these taxes into insurance and distribution effects. This allows us to determine how the sign of the optimal taxes on capital and labor depend on the nature of the shocks and the degree of heterogeneity among consumers' income, as well as on the way in which the tax revenue is used to provide lump‐sum transfers to consumers. When shocks affect primarily labor income and heterogeneity is small, the optimal tax on capital is positive. However, in other cases a negative tax on capital is welfare‐improving.     

The Effectiveness of Consumption Taxes and Transfers as Insurance Against Idiosyncratic Risk

We quantitatively evaluate the effectiveness of a consumption tax and lump-sum transfer program as insurance against idiosyncratic earnings risk. We use a heterogeneous agent, incomplete markets model in which households adjust savings and employment in each period in the presence of idiosyncratic productivity risk and a borrowing constraint. The model is calibrated to the U.S. economy. We find a weak insurance effect of the consumption tax and transfer program. Expanding the tax and transfer program from the current U.S. level increases the capital-output ratio and reduces the interest rate. Consumption inequality also decreases only slightly.     

Reverse Mortgage Loans: A Quantitative Analysis

Reverse mortgage loans (RMLs) allow older homeowners to borrow against housing wealth without moving. Despite rapid growth in this market, only 1.9% of eligible homeowners had RMLs in 2013. In this paper, we analyze reverse mortgages in a calibrated life‐cycle model of retirement. The average welfare gain from RMLs is $252 per homeowner, and $1,770 per RML borrower. Bequest motives, uncertainty about health and expenses, and loan costs account for low demand. According to the model, the Great Recession's impact differs across age, income, and wealth distributions, with a threefold increase in RML demand for lowest income and oldest households.     

Debt Overhang and Lack of Lender's Commitment

The debt overhang of sovereigns or firms is modeled in the recent literature as a constrained efficient outcome of dynamic debt contracts under the lack of the borrower's commitment, where debt relief is not Pareto-improving. The early literature observes another type of debt overhang where the borrower is discouraged from expending effort, anticipating the lender to take all output ex post. We show that this inefficiency is due to the lack of the lender's commitment and debt relief is Pareto-improving. Nevertheless, debt overhang may persist, as frictional bargaining over debt relief can take a long time.