The overriding objective of this research was to develop an understanding of Iran's policy environment, within which the country's mining sector operates, in relation to that of the rest of the world. In an effort to diversify the country's economy, the first five-year development plan (FFYDP) provided a solid structure for the development of the Iranian mining sector. Although the plan attached high priorities to increasing the share of the private sector in mineral activities, the actual capital invested by this sector in mining projects was much less than anticipated during the plan period. This observation constitutes the early context for this research. / To develop that understanding, a multi-level methodology for both the Iranian policy environment and its international counterparts was adopted. For Iran's policy environment, this multi-level methodology covered: (1) A comprehensive assessment of government Policies for the mineral sector as well as the sector's performance during the FFYDP. (2) A thorough examination of the views and comments of all active stakeholders, including Ministry of Mines and Metals (MMM) officials, mining company executives, and co-operatives and individual operators. This information collection was accomplished in three phases: informal discussions, interviews, and formal questionnaires with debriefing follow-ups, where the respondents made many comments on most aspects of the formal questionnaire. (3) An objective examination of financial statements of mining enterprises was also performed. / The comparison of Iran to the international context consisted of two major parts: (1) An assessment of the policy environment of three mineral-endowed developing countries through case studies, and (2) A detailed examination of the views and comments of large international mining enterprises. / This parallel and comparative approach has led to an overall finding that Iran's mineral policy environment has been relatively ineffective in attracting additional investment to the sector. To remedy this situation, policy recommendations, based on the analysis and implication of all components of the above research, are put forward. However, some challenging research questions remain, a list of which constitute promising areas of future research.

<p> According to a report by the World Health Organization, 65 million people worldwide need wheelchairs to regain mobility. Many of these people are unable to afford the devices they need and current makeshift solutions are unsuitable for a variety of reasons. I am a volunteer for Intelligent Mobility International (IMI), a non-profit that seeks to address this situation by producing and distributing durable, inexpensive wheelchairs in the developing world. This thesis designs a study to gauge the impacts receiving an IMI wheelchair has on the lives of people with disabilities and their families. This measure can then be used in the future when Intelligent Mobility evaluates different program options and demonstrates to funders the positive impacts of their donations. The study involves a randomized field trial in Tamil Nadu, India. Candidates for the trial will be identified by a local grass roots organization and verified by IMI to be appropriate candidates for the wheelchair. A total of six hundred candidates will be chosen to represent a good mixture of gender, education, household size and age of the target population, and then randomly assigned to either the treatment or control group. Participants in the treatment group will receive a wheelchair at the start of the year and those in the control at the end of the year. The two groups will then be surveyed on many dimensions of their lives using both open-ended ethnographic interviews and a numerical categorical survey both at the start of the year and the end of the year to estimate the impacts of the wheelchair. The ethnographic interviews will help ensure that the participants' views are captured accurately and will permit a more realistic interpretation of the study's qualitative results. The study design also reviews current literature on disability in India, the plan for implementation of the study, the methodological concerns in the design, and the ethical considerations involved.</p>

<p>An important factor in the rise of health care costs is the structure and performance of health care markets. This is an area in which policy can be particularly effective. Health care markets are characterized by complex interactions between consumers, physicians, insurers, facilities, and government agencies. Physicians, insurers, and facilities operate under a mix of objectives and governance structures. The many varieties of objectives, and governance structures can be broadly categorized as for-profit, not-for-profit, and governmental. </p><p> In the three chapters that follow I construct a theoretical framework to analyze hospital behavior and use a 30 year panel of data on Californian hospitals to assess the validity of the models and to identify the impact of governance structure on behavior. Chapter II addresses firm objectives. I find that firms have a continuum of weighting allocations, with for-profit firms placing greater weight on profit, government firms placing greater weight on social objectives, and not-for-profit firms locating in a middle ground. All three types of governance structures display overlap in their objectives. </p><p> In Chapter III, I identify patterns in hospital entry and exit. Like most manufacturing industries, entering hospitals are significantly smaller than incumbent hospitals and exiting hospitals are significantly smaller than surviving hospitals. The patterns of entry and exit for hospitals vary systematically with both governance structure and geographic diversification. </p><p> In Chapter IV, I develop a model of hospital entry that explains heterogeneous entry size and firm survival. I find entry size to be a relatively important factor in firm survival. In general entering on a larger scale increases the probability of survival. Despite this fact many firms enter relatively small. The model that I develop resolves small entry as a rational choice for uncertain firms. </p>

<p> People make many decisions with consequences that are delayed, rather than immediate. Of particular interest are decisions in which long-term gains must be balanced against short-term costs. Such time trade-offs can be advantageous or deleterious to the decision-maker: the decision to abstain from immediately entering the labor force and instead pursuing a lengthy education benefits the educated in the long-term although their short-term wages are lowered. In contrast, the decision to overeat increases the short-term enjoyment of food but decreases long-term health. A large body of research in psychology has shown that the ability to delay gratification and elect long-term over short-term gains leads to superior life outcomes. </p><p> Expanding on this tradition, my thesis examines time-tradeoffs in two domains: first, I examine the resolution of time-tradeoffs in settings in which people are asked to explicitly decide between short-term and long-term gains. This line of work is closely connected to economic models of decision-making that account for the role of time in shaping decisions. I then transition to examining the resolution of time-tradeoffs in settings in which time trade-offs are implicit. Specifically, I examine the way in which people explore unfamiliar environments in order to maximize information. Maximizing information represents a time-tradeoff because the goal of obtaining information generally requires the decision-maker to eschew known sources of short-term rewards in order to explore new options whose benefits will be reaped only in the long-term. </p><p> Collectively, I describe a large body of experiments that examine these two classes of decision-making and put forward two new models of decision-making, the ITCH model of intertemporal choice and the MaxInfo model of exploratory decision-making, that account for the data from these experiments and extend the state of the art.</p>

<p> Policy makers face complex situations involving the analysis and weighting of multiple incentives that complicate the design of natural resource and environmental policy. The objective of this dissertation is to characterize policy makers' incentives, and to investigate the consequences of those incentives on environmental and economic outcomes in the context of wildfire management and environmental policy. </p><p> Wildfire management occurs in a dynamic uncertain environment and requires the coordination of multiple management levels throughout the course of a fire season. Over the course of a wildfire, management teams allocate response resources between suppression of fire growth and protection of valuable assets to mitigate damage with minimal regard for cost. I develop a model of wildfire resource allocation to show that 1) wildfire managers face the incentive to protect residential structures at the expense of larger and more costly fires, and 2) response resources are transferred to fires with more threatened structures constraining the set of resources available to manage other fires in the region. I find empirical evidence to support the predictions of this model with theoretically consistent regression models of wildfire duration, size, and cost using data from U.S. wildfires that occurred between 2001 and 2010. These results imply that continued housing development of wildland prone to wildfire will 1) further distort management incentives, 2) lead to larger and more expensive fires, and 3) provide support for fees on rural homeowners. </p><p> Governments facing political opposition to renewable energy subsidies may resort to augmenting the fixed cost of entry in order to induce environmental outcomes. In global markets, one government's entry policy creates either positive or negative pecuniary externalities in other regions. I develop a two-region model to investigate the behavior of rival governments setting strategic entry policy, and the subsequent impacts on welfare. The results indicate that competition between the rival governments prevents the social optimal level of entry and suggests a role for international environmental agreements.</p>

<p> This dissertation consists of two chapters that concern with the consumption cycle and corporate finance. The first chapter analyzes the role of durability in characterizing the consumption cycle. There is strong empirical evidence demonstrating that decreases in residential investments and durable expenditures are early indicators of economic downturns. Analogously, once the economy goes into recession, early increases in residential investments and durable expenditures signal economic recoveries. So far, little work has been done detailing the mechanisms explaining these important empirical stylized facts. In this article, I develop a general equilibrium asset pricing production model that includes durability and substitutability between perishable and durable service consumption. Results indicate that large shocks in the productivity of the capital accumulation process and a high elasticity of intertemporal substitution are both needed to create the correct timing of changes in durable expenditures and nondurable consumption characterized in the data. The study also uses this general equilibrium model as a framework to make predictions about the term structure of forward contracts settled on a national housing price index. Such work will create a foundation for further developing this important derivatives market.</p><p> The second chapter analyzes the link between debt maturity and the term spread. This chapter is co-authored with Pratish Anilkumar Patel. Evidence shows that a firm's debt maturity and term spread are intricately linked. Firms issue short term debt when the term spread is significantly positive and they increase maturity as the term spread decreases. The current literature explains this link with market frictions such as agency problems, asymmetric information, and liquidity risk. We explain the link between debt maturity and term spread using the trade-off theory of capital structure. When the term spread is small or even negative, transaction costs of debt rollover outweigh bankruptcy costs. Therefore, the firm optimally chooses to increase debt maturity. On the other hand, when the term spread is significantly positive, bankruptcy costs outweigh transaction costs of debt rollover. Therefore shorter debt maturity is optimal as it minimizes the chance of bankruptcy. In addition, we contribute to the current discussion in the literature concerning the speed of adjustments of capital structure, finding that firms are active in adjusting their capital structure. The model is consistent with a variety of stylized facts concerning debt maturity.</p>

Our research examines the decision to participate in crime using a dynamic model of individual choice under uncertainty. The motivation for studying this decision in a dynamic framework is twofold. First, it allows us to formulate a theory of rational criminal choice, where agents anticipate the future consequences of their decisions. Second, it permits explanation of the temporal pattern displayed in aggregate arrest data. Across different countries, cities, and time periods, the aggregate arrest rate is a unimodal and positively skewed function of age. The standard static approach to crime offers no insight into the cause of this empirical regularity. We study criminality in a dynamic context by introducing social capital into the economic theory of crime. Social capital measures the extent to which an individual is bonded to legitimate society. The social control theory of crime posits that bonds to society strengthen as the individual ages, increasing the cost of deviant behavior, making criminal acts less likely. This hypothesis is consistent with the temporal pattern displayed in aggregate arrest data. In our formulation, preferences and legitimate income depend on the individual's stock of social capital. Rationality is imposed by requiring agents to take these effects into account. We empirically implement our model using panel data on a sample representative of young men in urban areas of the United States. Estimation is complicated by an omitted regressor problem, which arises because there are two possible future states--apprehension and escaping apprehension. Only one state is realized for each individual and subsequently observed by the econometrician. However, the unobserved choices in the state not realized enter the Euler equations. We resolve this problem by replacing the unobservables with Monte Carlo draws from the conditional empirical distribution of observed outcomes and using a Simulated Method of Moments estimator. Our results provide evidence in support of a social capital theory of crime. We find that social capital affects both preferences and earnings in the legitimate sector. Further, as predicted by social control theory, social capital becomes increasingly important over the life-cycle. This raises the cost associated with crime, making its occurrence less likely.

This dissertation consists of four chapters. In the first chapter, a review is made of the research on international reserve demand in the last decade. The next three chapters offer alternative models of reserve demand. One motive for why foreign currencies are held by national central banks (NCBs) is to intervene in the foreign exchange market. A primary goal of the last three chapters is to incorporate such an intervention motive in modeling demand for foreign exchange reserves by the public sector. Another goal--more fully studied in the last chapter--is to assess the effects of exchange controls on demand for reserves. Disequilibrium regime-switching econometrics is the modeling framework employed. This methodology allows for the possibility that a different demand regime may be in effect in periods when the NCB is a net buyer of foreign currencies as compared to periods when it is a net seller. To deal with the effects of constant changes in the exchange control environment--which could alter demand behavior--a robust method is used which weighs down observations from periods where the standard model performs poorly. Some evidence is found that market intervention changes the response of demand for foreign reserves with respect to trade and the opportunity cost. This effect is not uniform across countries however. National demands for foreign reserves are also found to vary. Furthermore, the period where the model performs poorly are not characterized chiefly by heavy exchange controls but by political/economic shocks and uncertainty. Shocks and uncertainty alter demand for foreign currency reserves while exchange controls appear to be ineffective.

This dissertation is comprised of three separate essays that share a similar theme: physician private practices. The first essay revisits prior research that has proposed a general framework for physician cost function estimation. The econometric specification is a multi-product cost function, and my model addresses and deals with many measurement problems and data complications in physician practice surveys. In particular, I expand upon existing theory to include those practices that yield zero outputs. This modification allows allow me to utilize a more representative and larger sample. The results of my analysis confirm that previous estimates have yielded a downward bias in reported marginal cost estimates, a point often speculated in the literature but not formally addressed empirically. The second essay uses the econometric specification from the first essay to develop a means for testing market power in physician private practices. Using the 1998 American Medical Association Physician Socioeconomic Monitoring Survey, I test the hypothesis of physician collusion in an oligopolistic setting for five fields of specialty. The collusion hypothesis is tested in a traditional conjectural-variation framework that reveals physicians are not highly collusive. However, a Lerner index shows that physicians do possess a high degree of monopoly power, consistent with many of the claims brought forward by the Department of Justice, primarily due to consumer price insensitivity. The third essay uses the marginal cost estimates of the second paper to revisit the Harberger partial equilibrium approach for computing welfare loss. Deadweight loss estimates are computed by physician, practice, and office visit. The reported losses are indicative of a loss in consumer surplus from the monopoly power that physicians possessed in 1998. The third essay concludes by showing that significant price markups led to substantial losses in welfare by the consumer and third-party payer.

The simple market efficiency hypothesis implies that prediction errors, such as forward less spot exchange rates, will be orthogonal to elements of the information set. One can therefore test for market efficiency via ordinary least squares by regressing the prediction errors on pieces of information available at the time the predictions are made and checking if the intercept term and slope coefficients are jointly equal to zero. Two econometric complications have to be dealt with when testing for market efficiency in the above manner. The first complication arises from the fact that multi-period-ahead predictions lead to an inter-temporal band structure for the covariance matrix. This complication can be handled by employing Hansen's Generalized Method of Moments (GMM) estimate which takes explicit account of the band structure of the covariance matrix. The second complication arises from the fact that the disturbances in the regression may also be heteroskedastic. Insofar as heteroskedasticity might adversely affect inference, we propose a White-type test that indicates whether or not a covariance matrix correction for heteroskedasticity is necessary. The test essentially checks if the difference between the homoskedastic and heteroskedastic consistent forms of Hansen's GMM estimate tend towards zero. Monte Carlo experiments examining the performance of the proposed test show that at least in large samples, the White-type test works well under a variety of heteroskedastic specifications. By actually applying the above procedures to test the simple foreign exchange market efficiency hypothesis, we find that for particular regression specifications and data sets, it does not make a practical difference whether we base inferences on the homoskedastic or the heteroskedastic consistent forms of Hansen's GMM covariance estimate. For other data sets and regression specifications, however, we are able to reject market efficiency only if we use the appropriate form of Hansen's GMM estimate as determined by the White-type test.