Quadratic Hedging with Margin Requirements and Portfolio Constraints

We consider a mean-variance portfolio optimization problem, namely, a problem of minimizing the variance of the final wealth that results from trading over a fixed finite horizon in a continuous-time complete market in the presence of convex portfolio constraints, taking into account the cost imposed by margin requirements on trades and subject to the further constraint that the expected final wealth equal a specified target value. Market parameters are chosen to be random processes adapted to the information filtration available to the investor and asset prices are modeled by Itô processes. To solve this problem we use an approach based on conjugate duality: we start by synthesizing a dual optimization problem, establish a set of optimality relations that describe an optimal solution in terms of solutions of the dual problem, thus giving necessary and sufficient conditions for the given optimization problem and its dual to each have a solution. Finally, we prove existence of a solution of the dual problem, and for a particular class of dual solutions, establish existence of an optimal portfolio and also describe it explicitly. The method elegantly and rather straightforwardly constructs a dual problem and its solution, as well as provides intuition for construction of the actual optimal portfolio

Reducing Evasion Through Self-Reporting: Theory and Evidence from Charitable Contributions

Using a quasi-experimental design, I show that self-reported information requirements are effective at reducing evasion. I use a reform that simplified the reporting rules for tax deductions of noncash charitable contributions in the U.S. to show that weaker reporting requirements led to a large increase in the reported donations but that nearly 50% of these donations were untruthful. At the same time, individuals experienced a substantial reduction in their reporting costs, an average of $82 per person. Next, I provide a theoretical framework that accounts for the observed trade-off between evasion and compliance costs to determine the optimal information requirements. I show that reporting should only be imposed on individuals with reported donations above a pre-specified threshold and that the threshold is primarily governed by the type and magnitude of cheating. Model calibrations in the case of noncash charitable donation deductions show that an optimally chosen threshold would reduce the welfare loss due to compliance and evasion by 70%

Reducing Evasion Through Self-Reporting: Theory and Evidence from Charitable Contributions

Using a quasi-experimental design, I show that self-reported information requirements are effective at reducing evasion. I use a reform that simplified the reporting rules for tax deductions of noncash charitable contributions in the U.S. to show that weaker reporting requirements led to a large increase in the reported donations but that nearly 50% of these donations were untruthful. At the same time, individuals experienced a substantial reduction in their reporting costs, an average of $82 per person. Next, I provide a theoretical framework that accounts for the observed trade-off between evasion and compliance costs to determine the optimal information requirements. I show that reporting should only be imposed on individuals with reported donations above a pre-specified threshold and that the threshold is primarily governed by the type and magnitude of cheating. Model calibrations in the case of noncash charitable donation deductions show that an optimally chosen threshold would reduce the welfare loss due to compliance and evasion by 70%

Adjust Me if I Can’t: The Effect of Firm Incentives on Labor Supply Responses to Taxes

I provide theoretical and empirical evidence on the importance of statu- tory incidence in labor markets in the presence of asymmetric frictions. Using a theoretical model I show that labor supply responses are stronger when the statutory incidence of taxes or labor rules falls on firms, even when wages can adjust freely. I explore these mechanisms by studying labor responses to incentives generated by the “Mini-Job” program aimed at increasing labor supply of low-income individuals in Germany. Using administrative data, I show evidence of a strong behavioral response – in the form of sharp bunching – to the mini-job threshold that generates large discontinuous changes both in the marginal tax rates and in the total in- come and payroll tax liability of individuals in Germany. Sharp bunching translates into elasticity estimates that are an order of magnitude larger than has been previously estimated using the bunching approach. To ex- plain the magnitude of the observed response, I show that in addition to tax rates, fringe benefit payments also change at the threshold. Mini-job workers receive smaller yearly bonuses and fewer vacation days but are paid higher gross wages than regular workers. These results indicate that lower fringe benefits make mini-jobs attractive to employers, thus facilitating labor supply responses in accordance with the model’s predictions

Reducing evasion through self-reporting: Evidence from charitable contributions

In absence of third-party reporting, taxpayers are required to self-report information with various degrees of detail, ranging from uncorroborated claims to comprehensive records with receipts. Using a quasi-experimental design applied to noncash charitable contribution deductions, I show that even basic self-reporting requirements are effective at reducing evasion but impose large compliance costs on taxpayers. I find that simplified reporting requirements reduce reporting costs by $55 per person and substantially increase claimed donations. However, half of the new donations are due to evasion. Thus, information reporting should only be imposed on total reported donations above a pre-specified threshold