No / It is demonstrated that small marketable gambles that are unattractive to a Standard Risk Averse investor cannot be made attractive even if certain independent background risks that decrease expected marginal utility are added.

No / By assuming that all uninsurable risk is permanent, a closed form multi-period, multiple agent and multiple asset incomplete market asset pricing model is presented that allows for jump as well as diffusion risk to personal income.

This paper solves a long-standing open problem in mathematical finance: to find a solution to the problem of maximizing utility from terminal wealth of an agent with a random endowment process, in the general, semimartingale model for incomplete markets, and to characterize it via the associated dual problem. We show that this is indeed possible if the dual problem and its domain are carefully defined. More precisely, we show that the optimal terminal wealth is equal to the inverse of marginal utility evaluated at the solution to the dual problem, which is in the form of the regular part of an element of(L∞)* (the dual space of L∞). (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

We show that, for a utility function U: R to R having reasonable asymptotic elasticity, the optimal investment process H. S is a super-martingale under each equivalent martingale measure Q, such that E[V(dQ/dP)] < "unendlich", where V is conjugate to U. Similar results for the special case of the exponential utility were recently obtained by Delbaen, Grandits, Rheinländer, Samperi, Schweizer, Stricker as well as Kabanov, Stricker. This result gives rise to a rather delicate analysis of the "good definition" of "allowed" trading strategies H for the financial market S. One offspring of these considerations leads to the subsequent - at first glance paradoxical - example. There is a financial market consisting of a deterministic bond and two risky financial assets (S_t^1, S_t^2)_0<=t<=T such that, for an agent whose preferences are modeled by expected exponential utility at time T, it is optimal to constantly hold one unit of asset S^1. However, if we pass to the market consisting only of the bond and the first risky asset S^1, and leaving the information structure unchanged, this trading strategy is not optimal any more: in this smaller market it is optimal to invest the initial endowment into the bond. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

abstract: This work is driven by two facts. First, the majority of households in the U.S. obtain health insurance through their employer. Second, around 20% of working age households choose not to purchase health insurance. The link between employment and health insurance has potentially large implications for household selection into employment and participation in public health insurance programs. In these two essays, I address the role of public and private provisions of health insurance on household employment and insurance decisions, the distribution of welfare, and the aggregate economy. In the first essay, I quantify the effects of key parts of the 2010 health care reform legislation. I construct a lifecycle incomplete markets model with an endogenous choice of health insurance coverage and calibrate it to U.S. data. I find that the reform decreases the fraction of uninsured households by 94% and increases ex-ante household welfare by 2.3% in consumption equivalence. The main driving force behind the reduction in the uninsured population is the health insurance mandate, although I find no significant welfare loss associated with the elimination of the mandatory health insurance provision. In the second essay, I provide a quantitative analysis of the role of medical expenditure risk in the employment and insurance decisions of households approaching retirement. I construct a dynamic general equilibrium model of the household that allows for self-selection into employment and health insurance coverage. I find that the welfare cost of medical expenditure risk is large at 5% of lifetime consumption equivalence for the non-institutionalized population. In addition, the provision of health insurance through the employer accounts for 20% of hours worked for households ages 60-64. Finally, I provide an quantitative analysis of changes in Medicare minimum eligibility age in a series of policy experiments. / Dissertation/Thesis / Ph.D. Economics 2011

In this thesis two dierent problems regarding real options are studied. The rst paper discusses the valuation of a timing option in an irreversible investment when the underlying model is incomplete. It is well known that in a complete model there is no nite optimal time at which to invest if the underlying asset, in our case the value of the developed project, does not pay out any strictly positive cash ows. In an incomplete model, the situation is dierent. Depending on the market price of risk in the model, there could be an optimal nite investment time even though the underlying asset does not pay out any strictly positive cash ows. Several examples of incomplete models are analyzed, and the value of the investment opportunity is calculated in each of them. The second paper concerns the valuation of random start American perpetual options. This type of perpetuate American option has the feature that it can not be exercised until a random time has occured. The reason for studying this type of option is that it provides a way of modelling the initiating of a project, e.g. the optimal time to build on a piece of land, which can not occur until a permit, or some other form of clearance, is given. The random time in the project application represents the time at which the permit is given. Two concrete examples of how to calculate the value of random start options is given. / <p>QC 20160607</p>

Student Number : 8804388Y - MSc Dissertation - School of Computational and Applied Mathematics - Faculty of Science / This dissertation considers the pricing and hedging of contingent claims in a general semimartingale market. Initially the focus is on a complete market, where it is possible to price uniquely and hedge perfectly. In this context the two fundamental theorems of asset pricing are explored. The market is then extended to incorporate risk that cannot be hedged fully, thereby making it incomplete. Using quadratic cost criteria, optimal hedging approaches are investigated, leading to the derivations of the minimal martingale measure and the variance-optimal martingale measure. These quadratic approaches are then applied to the problem of minimizing the basis risk that arises when an option on a non-traded asset is hedged with a correlated asset. Closed-form solutions based on the Black-Scholes equation are derived and numerical results are compared with those resulting from a utility maximization approach, with encouraging results.

Thesis advisor: Peter Ireland / Thesis advisor: Matteo Iacoviello / The dissertation is composed by two chapters. In the first one, I study the role of credit constraints and incomplete markets in the short run transmission of monetary shocks, using the superneutrality result that would obtain from preference separability in the Sidrauski model under complete markets as a benchmark. I find that money demand heterogeneity stemming from binding credit constraints invalidates the superneutrality result. I show this result under two alternative settings. In a simple two agents model, with heterogeneity in the rates of time preference, whether positive shocks to the growth rate of money are expansionary or contractionary crucially depends on the transfer scheme adopted by the monetary authority to rebate seigniorage transfers: redistributional effects implied by symmetric lump-sum transfers are contractionary, while wealth-neutral transfers are expansionary. In a model with uninsurable idiosyncratic risk, the approximate aggregation property fails to hold due to the high degree of heterogeneity of money demand and to the properties of the cross-sectional distribution of money holdings, suggesting the inadequacy of the representative agent assumption and the need for a more elaborate approximation of the wealth distribution to predict prices. In the second chapter, we propose a real business cycle model with labor and credit market frictions in which borrowing is conditional on employment status. Relative to a conventional set up, and as long as credit is valued positively, our model generates a non-standard labor/leisure trade off that induces job applicants to accept lower wages and firms to post more vacancies, ultimately increasing employment. A shock to the demand of durable goods, by increasing the collateral value, reduce the opportunity cost of working, and generates an increase in employment and output. The transmission of a financial shock that increases the loan to value ratio, is dampened by the costs, in terms of leisure, incurred by the borrowers. We show that this mechanism is able to generate the positive comovement between outstanding household debt and employment observed in the data, whereas a conventional model, in which employment status is irrelevant for obtaining credit, predicts a counterfactual negative comovement. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

We address the issue of market incompleteness in the time dimension. Specifically, we focus on interest rate markets and the yield curve extraction. The lack of information about interest rates manifest itself in a non-invertible linear system. The usual approach to circumvent this problem is by applying various curve fitting methods - both parametric and non-parametric. We argue in favor of a novel method relying on information theory, which reformulates the ill-posed linear algebra problem into a well-posed optimization problem, where the linear pricing equations are used as constraints. Local cross entropy is used to determine the optimal solution among the admissible solutions, while all the input prices reflected in constraints are perfectly matched. Large-scale optimization package called AMPL is used extensively throughout this work to obtain the optimal solution as well as to demonstrate the implementation details.

Following [10] we continue the study of the problem of expected utility maximization in incomplete markets. Our goal is to find minimal conditions on a model and a utility function for the validity of several key assertions of the theory to hold true. In [10] we proved that a minimal condition on the utility function alone, i.e. a minimal market independent condition, is that the asymptotic elasticity of the utility function is strictly less than 1. In this paper we show that a necessary and sufficient condition on both, the utility function and the model, is that the value function of the dual problem is finite. (authors' abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"