In the first chapter, I investigate the welfare effect of the government subsidizing medical insurance. To that extent, I construct and simulate a partial equilibrium computational model of medical care consumption and choice of insurance contracts. I use the overall utility of agents as a welfare measure and find that it is not welfare improving to subsidize uninsured agents by taxing insured ones. In addition I use the framework to verify the insurance contract choice effect and find a strong insurance contract choice effect. In Chapter 2, I investigate the effect of the price setting process under managed health care plans, such as HMOs and PPOs, on prices, profits of insurance companies and medical care providers, and household’s welfare compared to the indemnity plans prevalent before the advent of managed care. I construct a simple game played between a representative insurance company and a medical care provider to determine the price of medical care paid by insured and uninsured households. In addition, insurance companies set premiums not through solving the usual principal-agent problem which forces a zero profit condition, but rather and more realistically by optimizing profits. The outcome of this game is compared to the outcome of the indemnity plans where no price negotiations would occur. In Chapter 3, I investigate the effect of the suggested reform to the United States’ tax code in treatment of housing assets. In particular, I study the effect of the abolishment of the preferential tax treatment of housing assets (tax deductible mortgage interest payments and tax-free imputed rents) on the ownership and foreclosure rates in the housing market. I construct a model where heterogeneous agents decide on housing tenure in which default on housing mortgages occurs in equilibrium. I use this model to quantify the effect of this preferential tax treatment. I find that the elimination of the preferential tax treatment of housing assets results in a 33.4% reduction in foreclosures. Specifically, only eliminating the tax deductibility of interest on mortgage payments leads to a 12.4% reduction in foreclosure rates, while only taxing imputed rents generates a 32.5% reduction in foreclosure rates. / text

Dans cette thèse, j’analyse le rôle des institutions dans deux domaines d’études: le marché du travail et celui du logement. Dans le chapitre 1 (avec Elisa Guglielminetti), je présente un modèle de recherche randomisée pour expliquer la sélection des nouvelles embauches entre contrats à court et à long terme. En exploitant une base de données italienne, on trouve que la probabilité d’obtenir un contrat permanent augmente avec une plus forte correspondance entre l’éducation du travailleur et son occupation. Dans le chapitre 2, j’explore l’effet d’une libéralisation des contrats à temps déterminé et trouve un effet négatif sur les nouveaux emplois à durée indéterminée. Les résultats valident les simulations du premier chapitre et confirment le rôle de la qualité de l’appariement dans le choix d’embauche des entreprises. Le chapitre 3 (avec Robert Gary-Bobo), étudie la distribution du logement et du patrimoine immobilier entre générations et, en trouvant un déséquilibre à faveur des plus âgés, identifie des instruments de taxation pour sa correction. / In this thesis, I analyze the role of institutions in two markets: labor and housing. In chapter 1 (joint with Elisa Guglielminetti), I use a random search model to study the sorting of new hires into open-ended and fixed-term contracts. The co-existence of these two types of contracts is explained by match heterogeneity. When permanent contracts are expected to last longer, firms offer temporary contracts to low-productivity matches and permanent contracts to highly productive ones. Match productivity is interpreted as the fit of worker’s skills to task requirements. This hypothesis is supported by matched employer-employee data from a large Italian region. I further perform a policy analysis, showing that reforms liberalizing fixed-term contracts encourage their use, have non-linear effects on aggregate employment, but reduce long-term unemployment. In chapter 2, I investigate the effect of a liberalization of fixed-term contracts, finding a negative effect on new open-ended hires. This result validates the simulations in the first chapter, and confirms the role of match quality as sorting mechanism between contracts of different lengths and protection levels. Chapter 3 (joint with Robert Gary-Bobo), studies the distribution of housing in an overlapping generation model. Finding its equilibrium inefficient, I devise a system of proportional taxes to restore optimality.

The main objective of the study was to analyze the potential tax collection from the informal rental housing market in Zambia, using household level rental housing data collected for the Lusaka Urban District by the Central Statistical Office (CSO) as a basis for computation and extrapolation to the national level. This data was used to analyze household monthly expenditure on housing (rent), the total number of households in rented accommodation, and the tax regime applicable on rental income, to estimate the potential tax revenue that could be realized from this emerging sector. The estimates indicate that about K9.7 billion revenue could be collected on income from rental housing in Lusaka Urban District alone and a total of K83 billion nationally per annum. This represents about 0.4 percent of the country’s GDP in 2007. Compliance needs to be improved and legislation revised to ensure that the landlords are compelled to remit tax to the Zambia Revenue Authority. The current legislation makes enforcement and compliance difficult as it places the statutory tax burden on tenants, who are very mobile. It is, therefore, recommended that the landlord is made responsible for the payment of taxes due on rental income and that any compliance requirements be enforced against the real estate/property that is generating the income. This study also examines the performance of the presumptive taxation regime in Zambia The study uses data from the Zambia Revenue Authority on revenue collection from presumptive taxes which were introduced to capture income from the informal sectors. The presumptive taxes already introduced in Zambia include: base tax, advance income tax and turnover tax for minibuses and taxi operators. To analyze the performance of the presumptive tax regime, the study utilizes data on imports made by those not registered for taxes, to estimate how much revenue could be generated by imposing a 3 percent turnover tax on the value of their imports at importation. The analysis shows that the Zambia Revenue Authority increased revenue collection from K5.3 billion in 2004 to K33.5 billion in 2007. This improvement in revenue collection is far below the potential, however, which is estimated at over K501 billion on imports of unregistered traders alone. To collect this revenue and expand the tax base, the tax authority needs to improve the administration of advance income tax on unregistered importers, and raise the advance income tax rate to a level where the importer is indifferent between paying the advance tax at the border and paying turnover tax inland.