This dissertation addresses one of the most academically intriguing issues in MIS, so-called "IT productivity paradox" which describes the failure of detecting positive contribution in productivity statistics by Information Technology investment while our economy has voraciously and restlessly spent money on them for the last few decades. Recent studies are showing startling contrast with the previous ones and there seems big discrepancy between firm level and national economy analyses. In order to unravel the paradox and the discrepancy observed. The author provides theoretical and methodological discussion and the empirical investigation on the methodologies used by previous research and conducted both firm-level and macro-economic analysis. The background investigation above shows that the recent studies defying the decades-old IT paradox do not pass rigorous methodological test based microeconomic production theories. The firm level analysis confirms our conjectures that the highly positive contributions reported by the recent studies are not reliable and thus shall not be read without caution. Our claim is supplemented by simulation studies as well. In addition to the microeconomic analysis, macroeconomic level study on major developed countries has been conducted. An emphasis is placed at the impact of information technology on the structural change of employment, and at the impact of the structural change on productivity. The potential contribution of this dissertation includes: (i) Using the same data set the prior studies used, we contrasts findings and methodologies with those in the previous studies. It calls for very careful attention to the methodology before we applaud for "positive" findings. (ii) It also provides a rare study in MIS on economic value of IT investment in macroeconomics and international contexts.

Prior research (Luft 1994) has shown in a between-subjects laboratory setting that individual decision makers are more likely to accept an employment contract containing an incentive described as a bonus than one with identical payoffs described in penalty terms. Each of these budget-based contracts has exactly two potential payoffs; which payoff a given subject receives depends on whether the subject's task performance meets (or exceeds) the budget. Luft's (1994) results are interesting because they demonstrate in an individual decision-making setting the empirical invalidity of the assumption in most formal economic analyses that people are indifferent between such alternative verbal descriptions. However, there is continuing debate and mixed evidence on the issue of whether decisional behavior evident in individual decision-making settings is also evident in market settings. This research tests whether a preference for bonus incentives characterizes equilibrium in a laboratory setting in which subjects serving as employers in half (the other half) of the markets compete with each other to attract subjects serving as workers by offering them bonus (penalty) contracts. Worker subjects are always free to choose a fixed-pay contract. Market outcomes were consistent with the prediction of no significant bonus preference evident at equilibrium.

This dissertation addresses the importance of conceptions of responsibility for contemporary theories of justice. I criticize recent defenses of liberalism which try to proceed without conceptions of responsibility. I argue that a conception of neutrality does not provide adequate support for defending a liberal theory of justice. I defend this claim by examining Brian Barry's recent defense of neutrality liberalism. His idea of neutrality reduces to an indefensible skeptical argument about conceptions of the good. I next examine John Rawls's account of political liberalism. I argue that his approach fails to appropriately address the persons and traditions that would be sacrificed within a Rawlsian liberal order. Rawls's notion of reasonableness and his argument from the burdens of judgment are insufficient bases to develop a liberal theory of justice. I then examine the idea of equality and its relationship with responsibility. Egalitarians describe the ideal of equality as the most fundamental notion for a theory of justice. They also interpret other traditions--such as the contractarian approaches of Barry and Rawls--in terms of this commitment to moral equality. Through a discussion of Ronald Dworkin's liberal egalitarianism, I argue that any plausible interpretation of moral equality must rely on an account of personal responsibility. Claims about responsibility, I argue, must be at the core of any theory of theory of justice. In the last chapter, I consider what a theory of justice should be about. I argue that the common assumption that justice is about devising principles to regulate institutions distorts how we should organize concerns of justice. Justice is about people treating each other with the respect and dignity that they are due. Problems about institutional design must be responsive to an account of individual responsibilities of justice, rather than the contemporary liberal approach of devising institutional principles prior to and with regulative primacy.

This study introduces a new theory, called group hegemony, that explains how a group of wealthy countries maintains the liberal economic order, and how this order helps sustain the economic disparity between the core and the periphery in the post-WWII era. The theory of group hegemony advances three propositions. First, the Group of Seven (G-7) has replaced the US as the hegemon. The evidence indicates that a hegemon exists. The concentration of power within the core has remained relatively constant since the early 1960s. The US is not responsible for this concentration of power since its economic superiority has declined, whereas the power of the G-7 has remained constant. The G-7 accounts for about three-fourths of the core's power throughout the post-war era even though it constitutes less than one-third of the core's membership. In the early post-war period, the majority of the G-7's power was attributed to the US, but by the mid-1970s, power was more evenly distributed among the G-7 countries. The evidence indicates that the G-7 is the group hegemon. The second proposition contends that the group hegemon maintains the stability of the liberal economic order. The G-7 is the only group with enough power to provide liquidity, manage exchange rates, maintain large open markets, and supply foreign investment. The G-7 countries coordinate their policies when necessary to stabilize the liberal economic order. They collectively intervened in the 1970s and 1980s to stabilize exchange-markets. They coordinated their policies to offset the stock market crash in 1987. They also helped ease the debt crisis, finance the Gulf War, and aid Russia and other economies in transition. The third proposition holds that the rules governing the liberal order help sustain the gap between the core and the periphery. The rules are biased in favor of the core. These rules include preferential treatment for core members, tariff peaks on goods of particular export interest to developing countries, and tariff escalation. The liberal economic order benefits all, but some more than others.

Over the past 20 years, growing water demand in Spain has greatly reduced river flows into Portugal. Increasing pressures are expected on northern regions of Portugal, such as the Entre Douro e Minho (EDM), to reduce water use and improve quality. Two models, one theoretical and the other empirical, are developed to analyze water use by EDM agriculture. The theoretical model considers firms consuming and polluting water with multiple inputs, outputs, emissions, interdependent externalities, and transaction costs. The empirical model considers a flexible quadratic restricted profit model of representative farms for the region. A programming approach is followed. The Maximum Entropy technique is used to recover the profit model. An unrestricted profit function is obtained from the restricted profit function. The theoretical results show that when water externalities are interdependent it is not efficient to control each externality independently. Several policies exist to control interdependent externalities. All policies can be cost-effective, in theory. In practice, the policies have many transaction costs. The links between inputs, emissions, and ambient effects often are unknown. The focus then is on reducing farm use of inputs causing externalities. The empirical results show an inelastic response to prices. Nitrogen and water are complements. Coordination is required to reduce the use of each input. The decline of the Common Agricultural Policy (CAP) supports reduces pressure on water resources. At prices expected in 2000, the subsidies required to maintain farm profits range from three million contos (20% nitrogen reduction) to twelve million contos (20% nitrogen reduction plus 30% water reduction). However, total predicted expenditure for the subsidy program is only 3.3 million contos, which is clearly insufficient. The marginal value of water is only 5.6 esc/m3. Receiving 50 esc/m3, EDM agriculture will release 450 hm3 of water, 60% of its use.

The analysis of the Mexican economy is important because some of its developments have had international repercussions, and the lessons learned from Mexico may be applied in other developing countries. This dissertation comprises three essays related to the Mexican economy. The first two are connected to the Mexican banking industry, while the third essay analyzes the Mexican economy since WWII from an endogenous growth perspective. The first essay investigates the functional relationship between concentration and interest-rates in the Mexican commercial banking industry. A fundamental contribution of this essay is the use of parametric, nonparametric, and semiparametric procedures to determine the functional form of the concentration and interest-rate relationship. We check for regularities across products, and over time. The semiparametric estimation dominates the other methods. The resulting functional form seems to support the prediction of the structure-performance paradigm of a positive concentration-price relationship. In the second essay we use Cox (1972) proportional-hazards models with time-varying covariates in order to identify the characteristics that cause Mexican banks to disappear. We conclude form this study that the evolution of the Mexican banking system has been determined by the asset quality, the earnings, and the liquidity ratios (CAMEL-type financial ratios). Moreover, we use the estimated time-varying coefficients to analyze the effects of moral hazard form risk-taking induced by the Mexican government deposit insurance scheme, FOBAPROA. We find that FOBAPROA affected the coefficients exacerbating financial problems already present. Finally, in order to analyze the performance of the Mexican economy since WWII, the third essay employs a two-country endogenous growth model. An implication of this growth model is that because of technology transfer, the U.S. (R&D-performing country) and Mexico (implementation R&D country) converge to parallel growth paths, as long as some minimum conditions in terms of institutions and human capital are met. We find suggestive evidence that a lack of adequate institutions and human capital base are likely to contribute to the explanation of the poor performance of Mexico's GDP per capita after the reforms in the 1980s.

This dissertation offers an investigation of the current issues in economics of the international airline industry. The two broad issues considered are deregulation of and consolidation on the international airline markets. The process of deregulation has been and will probably remain gradual. Moreover, restrictions are often removed in such a way that players are forced to play by different rules. In this context, I measure price effects of asymmetric entry barriers at London's Heathrow airport. I find that such entry restriction decreases the fares of the affected carriers. Concurrently, I find that the airport dominance effect, shown to exist for the US domestic market, applies to the international routes as well. On the basis of my results, I suggest the following danger in the process of the gradual deregulation of international aviation. Given the strong political influences and the current industry structure, we may end up getting locked into situations, where a carrier that dominates an airport may obtain preferential treatment on the respective international routes. This can prevent entry by the more efficient carriers and/or keep the less efficient airlines in operation. As far as airline consolidation is concerned, I develop a new model of price competition between international airline alliances and test its predictions. The primary focus is on the price effects of codesharing (connecting the partner airlines' networks) and antitrust immunity (allowing the partner airlines to jointly set fares across the unified network). I show theoretically that antitrust immunity may not have negative price effects in addition to that of codesharing. This finding is contrary to what has been suggested previously. Empirical analysis confirms the theoretical predictions.

This dissertation examines the consumption of commercial energy, electricity and petroleum products in Yemen for the period 1970-1990. The main objectives are: (1) analyzing the energy consumption in Yemen; (2) investigating the determinants of demand for electricity and petroleum products (3) projecting the values of petroleum consumption for the years 1991-2000; and (4) recommending measures to curb the rate of increase in the demand for energy and to reduce the dependence upon imported oil. This study found that economic growth in Yemen has had a major impact upon the demand for electricity and petroleum products, and that energy intensity had increased over time, indicating that economic growth of Yemen has been very energy intensive. The models that have been chosen in this study are based on the theory of demand. According to this theory, the demand for a good is a function of own price, price of substitutes, and income. The estimates given by the model for aggregate electricity over the period 1975-1990 improved when the number of customers was included in the demand equation. Income and the number of customers are the major determinants of electricity demand in Yemen; the estimated coefficient for price of electricity over the period was not statistically significant at the 5% level. In the case of the demand for electricity by sectors, the results are more useful than for aggregate electricity demand. Electricity consumption for the residential, commercial and industrial sectors was well modeled as a function of only price and income. Demand for electricity in the agricultural sector, however, was described best by a stock adjustment model. The estimated models for individual petroleum products showed that price for fuels and income are major determinants in explaining the variation in demand for these products. Overall, this study found that the future energy outlook in Yemen calls for increasing electricity and petroleum consumption. Moreover, current fuel efficiencies and the estimated fuel demand equations indicate increasing fuel prices, given growth rates of population and per capita GDP. Thus, issues to be considered by energy policy include welfare and economic growth implications of increasing fuel prices, energy conservation, and expanded domestic petroleum production.

Both static and dynamic aspects of oligopoly are discussed in the beginning of this thesis and four expectation schemes of dynamic oligopolies have been investigated and tested. Some modifications have also been added to an earlier computer program developed originally by Wu (1991) to improve the stability of the models. Computer simulation results are reported at the end of this thesis.

Economic valuation techniques for environmental goods and services can contribute to decisions regarding the sustainable use and preservation of natural resources. Several valuation techniques have been developed based on neoclassical economics. However, when markets fail these techniques are not applicable. An alternative approach that is less dependent on pervasive markets comes from the school of biophysical economics. This approach is based on the energy theory. According to this theory, the embodied energy of the ecosystem is estimated and a money value is assigned to it. This thesis uses a variation of a biophysical technique for the economic valuation of the above-ground biomass of a Colombian High-Andean forest. The biomass or physical organization and the diversity component of the contributory value of the forest are considered by the biomass technique. However, this technique fails to measure the ecological services component of this kind of value.