This study addresses the impact of Mexican illegal immigration on the U.S. labor market. It constitutes a first step towards developing rigorous structural econometric models that empirically analyze undocumented labor force dynamics. Structural estimation of the labor supply and the participation decision of illegal Mexican immigration requires the solution of intricate theoretical problems that have not been addressed in previous literature. The analysis developed here identifies those problems and proposes innovative solutions. In particular, undocumented participation in the U.S. labor market is studied in the context of life cycle theory and stochastic behavior. The empirical part of the analysis reviews the problems of sample selection and missing observations that characterize the available data on Mexican migration. The proposed empirical specification is evaluated employing limited dependent variables procedures, where a Tobit simultaneous equation model is solved using maximum likelihood methods. According to the empirical results, Mexican undocumented immigration may be viewed as a transitory phenomenon. Individuals switch back and forth between Mexico and the U.S. reacting not only to income differentials, but also to social, family and economic attachments in their home-communities. Mexican workers seem to have little incentives to invest in human capital specific to the U.S., such as the ability to speak English. This behavior may be result of the partial transferability of Mexican skills, i.e. formal education, to the secondary market in the United States. Finally, contrary to conventional wisdom, the empirical evidence suggests that exogenous increases in U.S. wages, i.e. a non-expected hike in the legal minimum wage, may actually discourage Mexican undocumented participation in the U.S. labor market.

The Apartheid system in South Africa came to a close recently and a new majority government is ruling. This government represents a poor majority of the population, and there is great pressure on them to redistribute wealth in favor of their supporters, the poor. This thesis consists of three essays. The first estimates the distribution of personal wealth in South Africa according to the estate multiplier method. It is found that the distribution is skewed, but not more so than in countries for which similar studies have been done. The distribution of wealth is, however, distributed along racial lines, which makes the distribution politically unacceptable. The white minority which constitutes 16 percent of the total population, owns more than 90 percent of all personal wealth. The second part studies the major political role players in South Africa and their behavior in the Constitution making process that is still underway. A model of optimal behavior by political groups is constructed, and it is found that the majority government in South Africa will act rationally if they opt for majority rule in a unitary state. That is exactly what the ANC-government has been doing since the beginning of the negotiation process. The behavior of the other groups is also found to be rational and predictable within the context of the model. The third part of the thesis consists of a computable general equilibrium model with overlapping generations. Three groups are modeled--a rich group, a middle class, and a poor group. A government implements three possible redistributive policy measures. First, the tax on the capital income which accrues to the two more affluent groups, is increased; second, an estate tax is implemented, and third, the sales tax is increased. The first policy measure improves upon the wealth distribution, but is inefficient. The second policy, which is implemented according to the lifetime endowment view of tax equity, generally improves upon the wealth distribution, and is relatively efficient under certain assumptions. The third policy may be very harmful to the poor.

This dissertation focuses on the heterogeneous production technologies in banking and finance within the context of efficiency-analyses. The first essay studies the cost efficiency of Turkish banking industry. Studies of bank efficiency tend to draw conclusions from pooled estimates, assuming that all banks in a sample use the same technology, or estimates based on a priori classifications of the banks. It is well known that efficiency rankings may be corrupted if banks that use different technologies are pooled together in estimating the technological frontier with respect to which inefficiency is estimated. We model unobserved heterogeneity in banking technologies as a mixture model, and investigate the efficiencies of 53 Turkish banks using likelihood-based stochastic frontier analysis for the period 1990--2000. Our likelihood-based analysis finds no evidence of heterogeneity along the state vs. private and Islamic vs. conventional dimensions. The estimated classifications and mixture components have intuitive ex post institutional explanations. The second essay investigates the labor efficiency of Turkish banks for 1990--2000 by using a flexible translog functional form where the demand for labor is a function of loans, deposits, number of branches, total fixed assets and a time variable. The model allows for the possibility that at any point banks' observed employment may not be optimal. We expand the labor-use model by utilizing the EC (Estimation-Classification) estimator to obtain data-driven identification of bank-technology-classes in our sample. The third essay uses a set of semiparametric efficient (SPE) estimators for a panel data of 32 developing countries to investigate the effect of sources of external financing on production efficiency. The idea of production frontiers for firms in a given industry is applied in a macroeconomic context in which countries are producers of output (GDP) given inputs (capital and labor) and some external factors (i.e. debt, equity and foreign direct investment (FDI) stocks). Using two recent datasets, we are able to investigate the individual impact of foreign liabilities, namely debt, equity and FDI, on production efficiency. The estimates indicate that FDI plays a more prominent role of promoting production efficiency than debt or equity financing for developing countries.

In this dissertation, the risk adjusted rate of return (RAROR) that utilizes the directional distance function (DDF) approaches is developed to integrate conventional RAROR in a consistent manner. The sensitivity and the probabilistic analysis for DDF-RAROR are also illustrated. The DDF-RAROR is used to evaluate security performance of media stocks (1997--2001). Conglomeration in media industry has attracted public concern for a century. The results indicate that stock investors prefer conglomerate stocks, and this preference is explained by the market sentiment rather than by the underlying business prospect. This observation is confirmed through both nonparametric ranking test and nonparametric regression technique. Especially, the underlying return on equity (ROE) significantly influences the corresponding security performance.

Rent controls lead not only to a smaller market quantity of rental housing; they also result in a deterioration in the quality of available rental housing. A model of the labor market is presented in which the same kind of adjustment can take place when a minimum wage is imposed. The quality of a job is represented by the effort level which workers expend on the job. We assume that firms can observe and control this level of effort. This assumption may be particularly true of the lower paying jobs which would be most affected by the imposition of a minimum wage. Although effort can be controlled, there are limits to how much effort the firm would enforce. To begin with, enforcing effort is costly. In addition, workers have the option of working elsewhere or engaging in non-market activity. We examine the Pareto optimum and short-run perfectly competitive versions of this problem. The two coincide when the on-the-job utility takes a form which eliminates income effects. When a minimum wage is imposed, the short-run perfectly competitive system is no longer Pareto optimal, even in the "second best" sense. For commonly used functional forms, we find that required effort increases enough to make utility on the job decline when a minimum wage is imposed. This contradicts the classical notion that the workers who keep their jobs under a minimum wage are better off. The overall welfare generated by the system also declines. This type of adjustment in the quality of jobs is not accounted for in the standard analysis. When the adverse effects of a minimum wage are measured only in terms of lost employment, therefore, they may be underestimated.

Taking into account the social and economic benefits of telecommunications development, universal access has gained remarkable importance in the sector's regulation. From a global perspective, the penetration of telephone lines in Colombia is quite poor; there are only seventeen lines for every one hundred people. In this thesis, access to telecommunications from a structural viewpoint is examined. According to social, economic, and historic factors, the approach to universal service in rural areas must differ from that of urban centers. While stronger government intervention is required in the Colombian countryside, the same rigid universal service regulation is not necessary in the main urban areas. This assumption is supported on two main arguments. Firstly, universal service regulation might protect self-serving interests while constraining the market from increasing the number of users. Secondly, the starting point of the rigid cross-subsidization structure is the economic capability of customers. This policy restricts greater penetration because it fails to consider people's communication interests and needs as the core objective of the telecommunications policy. Under a different approach, telecom operators might be able to accomplish successful market segmentation according to the particular needs of different regions and communities. Efficient market segmentation would acknowledge the low-income customer's potential in the market place, while at the same time encouraging innovation by operators. Thus, affordability and profitability would not oppose each other. / This thesis considers three different zones in the Colombian territory, showing that the Communications Fund's investment should be used in regions with greater levels of violence, poverty and migration. In addition, we propose that a universal access policy should be applied in order to shrink the already large gap between rich and poor people in the heterogeneous Colombian society.

<p> The second chapter examines how both domestic and foreign tobacco regulations affect the flow of tobacco trade. I develop a gravity equation incorporating a comprehensive set of domestic and foreign tobacco regulations into a country's tobacco import demand and estimate their bilateral effects. The results suggest a country's tobacco imports are significantly affected by their trading partner's tobacco regulations. There are two important results: spatial regulations reduce tobacco trade regardless of trade direction and marketing regulations in importing countries may actually increase tobacco imports. These results highlight the importance of understand regulations in an increasingly multilateral economy. </p><p> The third chapter investigates the effects of varying levels of access and excludability on a common pool resource with intrinsic quality characteristics. I analyze the case of deer hunting on leased properties by hunting clubs and estimate the lease size elasticity of both harvest and antler quality. The results suggest lease size has a small but significant effect. For all clubs with smaller than average hunting leases, a simulated increase to the average size results in approximately a 4.5 percent increase in the average antler quality of deer harvested. Although I analyze properties leased by hunting clubs, the results are applicable to various other management scenarios. </p><p> The fourth chapter develops the relationship between excess demand and purchase options. I illustrate a mechanism allowing firms to smooth sales across periods with uncertain quality and increase expected profit over the market clearing strategy. By "underpricing" high quality goods and offering a purchase option guaranteeing a single price regardless of quality, firms create excess demand and increase consumer willingness to pay for their purchase option. The firm maximizes profit by choosing a guaranteed price low enough to create sufficient excess demand and consumer willingness to pay for the purchase option that markets clear when quality is low. Using a numeric example, I demonstrate a case where this behavior increases profit over the market clearing strategy.</p>

<p> Behavioral economists have attempted to show that human iterated reasoning faculties discourage non-equilibrium, non-convergent game dynamics. But what if individuals iterating through each other's strategic intentions are instead driving complex collective dynamics? The results in this manuscript demonstrate that bounded "what you think I think you think" reasoning can cause sustained deviations from Nash equilibrium and other fixed-point solution concepts. Supporting my thesis are a series of six experiments, a revisitation of a classic game theory experiment, a variety of computational models, and an analysis of a real-world dataset with highly motivated agents. I also introduce two new games, the Mod Game and the Runway Game. By bridging human higher-level reasoning and animal collective behavior, this work challenges attitudes in economics that complex social dynamics can--or even should--be designed away. </p>

<p> The purpose of this study is to determine how economic factors correlate with and have an effect on enrollment at community colleges and provide benchmark enrollment strategies for use by community colleges in the future. A cluster sampling of 22 branch campus locations at 9 community colleges in Mississippi and their respective counties was selected. The independent variables used were median household income, percentage of persons below the poverty level, and unemployment rates. </p><p> A statistical correlation and regression was conducted to determine if economic factors (median household income, percentage of persons below the poverty level, and unemployment by county) had any correlation or an effect on the decrease or increase in enrollment at the respective community college campus. The correlation and statistical effect based on the regression model used demonstrated that median household income and poverty levels had the strongest correlation and the most statistically significant effect on community college enrollment in Mississippi. Unemployment had a very weak correlation and no statistically significant effect on the sample for community college enrollment for Mississippi during this period. There were some exceptions in which certain community college campuses and their respective county unemployment rates had a very high effect on enrollment for that specific campus and that specific period. </p><p> There were 6 phone interviews conducted following the analysis of the datasets to determine any internal or external causes to enrollment decreases and increases during this period. 4 of the 6 colleges responded. Of the colleges that responded, 2 saw increases and 2 saw decreases. The predominant enrollment factor denoted by the interviewee was retention and cohesive interdepartmental focus toward recruitment, which resulted in increased enrollment. Of the colleges that saw decreases and were interviewed, it was noted that enrollment personnel were not prepared for the enrollment decrease and could have been. </p><p> Target markets with higher income and lower poverty levels perform better during harsh periods of challenge for enrollment at community colleges. Increased retention and interdepartmental cohesion produces better preparation for challenging periods of declining enrollment.</p>

<p> This thesis considers the structural characteristics of online criminal networks from a technical and an economic perspective. Through large-scale measurements, we empirically describe some salient elements of the online criminal infrastructures, and we derive economic models characterizing the associated monetization paths enabling criminal profitability. This analysis reveals the existence of structural <i>choke points:</i> components of online criminal operations being limited in number, and critical for the operations&rsquo; profitability. Consequently, interventions targeting such components can reduce the opportunities and incentives to engage in online crime through an increase in criminal operational costs, and in the risk of apprehension.</p><p> We define a methodology describing the process of distilling the knowledge gained from the empirical measurements on the criminal infrastructures towards identifying and evaluating appropriate countermeasures. We argue that countermeasures, as defined in the context of situational crime prevention, can be effective for a long-term reduction in the occurrence of online crime.</p>