Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 5 uppsatser.

In the first chapter, we propose a new method for modeling competition in electricity spot markets, namely, by approximating the supply functions of the competitors with cubic splines. We argue that this method is preferable to approximation by linear or piecewise-affine functions, which have been the main approaches to date. We apply our method to the firms competing in the Texas market. We also show that, more often than not, we will observe that the marginal revenue functions of the firms will have increasing segments which may lead to multiple profit-maximizing optima for a firm. In the second chapter, we model the effects of forward contracting on power prices in wholesale electricity markets. In contrast to most of the previous literature, we explicitly model power retailers, and introduce risk aversion. As expected, increasing the number of players have pro-competitive effects on the spot price of electricity. We also find that as the generators bid more competitively, spot and forward prices converge. Our model also captures the effects of level and variability of power demand on the players' contracting decisions. In the final chapter, we depart from equilibrium approach and utilizing agent-based modeling, analyze the effects of increased power demand price sensitivity on the level and volatility of power prices. We find that as the price sensitivity increases at the demand side, power price as well as its volatility decrease significantly. We also argue that the celebrated Herfindahl-Hirschman Index to measure market concentration is not a suitable metric for power markets.

Most energy sources are derived from the sun, directly or indirectly. Stopping the increase of heat-trapping carbon dioxide in the atmosphere will likely require more reliance on current rather than ancient terrestrial solar input. Yet which forms of renewable energy are most appropriately used is a significant question for the twenty-first century. This dissertation concerns the potential supply of biomass energy crops as a renewable energy source in Massachusetts. Biomass represents a low-efficiency solar collector, and supplying society with an important portion of its energy from biomass would require a great deal of land. The cellulosic biomass crop evaluated in this research is switchgrass, among the most studied of possible biomass crops. The study looks at biomass energy crop potential from three perspectives. First, a biomass crop supply function is developed for switchgrass by 1) using a GIS model to estimate land availability by current land use and soil type; 2) using a crop-growth simulation model to estimate potential switchgrass yields; 3) estimating marginal production cost by land parcel; and 4) calculating a supply function from marginal production costs. Total technical potential is estimated to be about 1.3 million dry metric tons of switchgrass per year, though financial constraints would likely limit production to some portion of the estimated 125,000 metric tons per year that could be produced on existing grasslands. Next, the study examines circumstances under which landowners might opt to make land available for biomass crop production. The social challenge of minimizing biomass energy cost is described. Potential biomass crop landowner decisions are characterized in a theoretical utility maximization model, with results suggesting that non-price attributes of crop production are likely important to landowners. Finally, an empirical study using a landowner survey assesses interest in growing biomass crops, and uses contingent valuation (CV) to estimate landowner willingness to accept (WTA) land rent for biomass crops. The median estimate is $321/ha/yr, with a much-higher mean estimate of $658/ha/yr (based on a parametric estimator). While the realistic potential for biomass crops is some fraction of technically feasible potential, there are other potentially important roles for biomass crops in Massachusetts, for example in preserving unused farmland that would otherwise revert to forest.

<p>In most electricity markets, producers submit supply functions to a procurement uniform-price auction under uncertainty before demand has been realized. In the Supply Function Equilibrium (SFE), every producer commits to the supply function that maximises his expected profit given the bids of competitors. </p><p>The presence of multiple equilibria is a basic weakness of the SFE framework. Essay I shows that with (i) symmetric producers, (ii) perfectly inelastic demand, (iii) a reservation price (price cap), and (iv) capacity constraints that bind with a positive probability, a unique symmetric SFE exists. The equilibrium price reaches the price cap exactly when capacity constraints bind.</p><p>Another weakness is difficulty finding a valid asymmetric SFE with non-decreasing supply functions. Essay II shows that for firms with asymmetric capacity constraints but identical constant marginal costs there exists a unique and valid SFE. Equilibrium supply functions exhibit kinks as well as vertical and horizontal segments. The price at which the capacity constraint of a firm binds is increasing in the firm’s share of market capacity. The capacity constraint of the second largest firm binds when the market price reaches the price cap. Thereafter, the largest firm supplies its remaining capacity with a perfectly elastic segment at the price cap. Essay III presents a numerical algorithm that calculates a similar SFE for asymmetric firms with increasing marginal costs. </p><p>Essay IV derives the SFE of a pay-as-bid auction such as the balancing market for electric power in Britain. A unique SFE always exists if the demand’s hazard rate is monotonically decreasing, as for a Pareto distribution of the second kind. Assuming this probability distribution, the pay-as-bid procurement auction is compared to the SFE of a uniform-price procurement auction. Two theorems in Essay V prove that the demand-weighted average price is (weakly) lower in the pay-as-bid procurement auction. </p>

In most electricity markets, producers submit supply functions to a procurement uniform-price auction under uncertainty before demand has been realized. In the Supply Function Equilibrium (SFE), every producer commits to the supply function that maximises his expected profit given the bids of competitors. The presence of multiple equilibria is a basic weakness of the SFE framework. Essay I shows that with (i) symmetric producers, (ii) perfectly inelastic demand, (iii) a reservation price (price cap), and (iv) capacity constraints that bind with a positive probability, a unique symmetric SFE exists. The equilibrium price reaches the price cap exactly when capacity constraints bind. Another weakness is difficulty finding a valid asymmetric SFE with non-decreasing supply functions. Essay II shows that for firms with asymmetric capacity constraints but identical constant marginal costs there exists a unique and valid SFE. Equilibrium supply functions exhibit kinks as well as vertical and horizontal segments. The price at which the capacity constraint of a firm binds is increasing in the firm’s share of market capacity. The capacity constraint of the second largest firm binds when the market price reaches the price cap. Thereafter, the largest firm supplies its remaining capacity with a perfectly elastic segment at the price cap. Essay III presents a numerical algorithm that calculates a similar SFE for asymmetric firms with increasing marginal costs. Essay IV derives the SFE of a pay-as-bid auction such as the balancing market for electric power in Britain. A unique SFE always exists if the demand’s hazard rate is monotonically decreasing, as for a Pareto distribution of the second kind. Assuming this probability distribution, the pay-as-bid procurement auction is compared to the SFE of a uniform-price procurement auction. Two theorems in Essay V prove that the demand-weighted average price is (weakly) lower in the pay-as-bid procurement auction.

Made available in DSpace on 2010-04-20T21:00:20Z (GMT). No. of bitstreams: 3 antonymartinsturma2003.pdf.jpg: 10954 bytes, checksum: 755884a503849fb2d792c7b263581245 (MD5) antonymartinsturma2003.pdf: 475640 bytes, checksum: 840c5bb2f74118f5c36c3e06ef0ce1c6 (MD5) antonymartinsturma2003.pdf.txt: 106505 bytes, checksum: e68910d74785c53f6f39d185ac2ae3dd (MD5) Previous issue date: 2006-01-16T00:00:00Z / The main purpose of this paper is the analysis of the market share of different strategic groups that forms the internet agencies industry in Brazil, as well as the changes occurred by modifications in its critical variables, such as price, advertising and technology investment and availability of man power. For that reason the method of computer simulation, using system dynamics, was adopted. In approximately ten years, we witness an intense development of the internet agencies industry in Brazil, with the increase of use of interactive devices and the consolidation of this new economic sector. The main service provided by this industry bacame strategic for all the other industries, reason why this study is so important. This paper uses computer simulation, in particular system dynamics, for two reasons. The first reason is the lack of trustworthy information available about the sector, and the second is that an econometric approach would not be able to deal with a complex situation, such as, the behavior of market share variations in different strategic groups of the same industry. The system dynamics technique revealed itself extremely useful, especially due to the volume of data interrelated. Moreover, the adoption of this technique allowed to identify non-trivial patterns, especially the ones related to the analyses on changes in the degree of differentiation between the different strategical groups. The paper is divided in five briefly described sections. The first section, "Introduction", presents the subject and the characteristics that affect the performance of the firms in the industry. The following topic, "System Dynamics", describes the technique created by J. W. Forrester, used in this work, as well as the reasons for its choice as method for the development of the simulations. The third section, "Description of the Industry", describes the sector using the approach created by F. M. Scherer - structure-conduct-performance (SCP). The fourth section "Simulations", describes the models created in the paper, as well as the main results. Finally, the fifth section, "Conclusions", comments the most important results developed. / Esta dissertação tem por objetivo analisar a participação de mercado dos diferentes grupos estratégicos que compõem o setor de agências de internet no Brasil, bem como as mudanças decorrentes de alterações nas variáveis críticas de concorrência, tais como preço, investimento em propaganda, investimento em tecnologia e disponibilidade de mão-de-obra. Para tanto, será aplicado o método de simulação computacional, utilizando-se dinâmica de sistemas. Em aproximadamente dez anos, houve um intenso desenvolvimento do setor de agências de internet no Brasil, com o amadurecimento deste novo setor econômico e a ampliação dos dispositivos interativos empregados. A atividade prestada por esse setor ganhou papel fundamental para as estratégias de todos os demais setores econômicos, razão pela qual o seu estudo é de grande relevância. Nesse estudo, foi empregada uma abordagem de simulação computacional, em particular dinâmica de sistemas, por dois motivos. Por um lado, existem poucas informações disponíveis e confiáveis sobre o setor, pois trata-se de um ramo novo e ainda em processo de consolidação. Essa escassez de dados e ausência de informações secundárias impossibilitam a adoção de análises quantitativas por meio de técnicas econométricas. Por outro, a simulação matemática por um modelo estruturalmente fechado não seria adequada para tratar situações complexas, como, nesse caso, a análise do comportamento de diferentes grupos estratégicos de uma mesma indústria. A simulação por dinâmica de sistemas permite maior flexibilidade para acomodar diferentes cenários e estruturas de indústria, sendo, portanto, mais adequada para o propósito desta dissertação. A técnica de dinâmica de sistemas adotada se revelou útil, especialmente em razão do volume de dados inter-relacionados ao longo do trabalho, e das efetivas influências recíprocas percebidas entre as variáveis. Além disso, a adoção desta técnica permitiu identificar padrões contra-intuitivos, o que se revelou acertado, principalmente no que concerne às análises sobre mudanças no grau de diferenciação entre os diferentes grupos estratégicos analisados. O trabalho divide-se em cinco seções brevemente descritas a seguir. A primeira seção, “Introdução”, apresenta o tema e as características que afetam o desempenho das firmas do setor. O tópico seguinte, “Dinâmica de sistemas”, descreve a técnica criada por J. W. Forrester, empregada neste trabalho, bem como as razões para sua escolha como método para o desenvolvimento das simulações. A terceira seção, “Descrição da indústria”, retrata o setor em questão através da abordagem estrutura-conduta-desempenho (ECD) criada por F. M. Scherer. A seguir, em “Desenvolvimento das simulações”, são detalhados os modelos desenvolvidos e o resultado das principais simulações, analisados sucintamente. Por fim, a quinta seção, “Conclusões”, trata dos resultados mais relevantes desta dissertação.

本文設立一個採行浮動匯率制度、資本不完全移動且具有完全預知特性的的小型開放經濟體系，同時運用體制崩潰的方法，據以探導：當一個國家遭受未預料到商品供給面干擾，而對商品市場的供需產生變化，此時商品市場上因有超額需求的存在而使得物價持續上揚時，政府將會透過對名目貨幣供給數量的調整來抑制物價上揚的情況下，整體相關經濟變數的動態調整行為。由於民眾的預期具有完全預知的特性，因此當他們觀察經濟現象而事先掌握到貨幣當局於未來將採取的行動時，就會提前有所反應；也就是說，在貨幣當局尚未調整名目貨幣供給、體制尚未崩潰之前，經濟體系便會已先行調整。 研究的結果指出，政府所能忍受的物價上限水準不僅與體制崩潰的時機息息相關，同時也決定了體制是否崩潰。而政府所能忍受的物價上限水準的高低與資本移動性的相對大小則同時左右了體制崩潰過程中，匯率的動態調整型態。此外，在放寬充分就業水準的假設下，資本移動性的相對大小也影響了產出水準的調整路徑。

[pt] Este trabalho analisa um mercado de eletricidade em que os geradores declaram funções de custo quadráticas para o operador da rede e também suas disponibilidades máximas de produção. O operador, então, determina as quantidades a serem produzidas por cada gerador de modo a atender a uma demanda inelástica, ao menor custo possível. Estabelecem-se alguns resultados que permitem computar os equilíbrios de Nash deste modelo e descrevem-se algumas de suas propriedades, tais como condições de existência. / [en] This work analyzes an electricity market in which generators declare quadratic cost functions for the grid operator and also the maximum capacity available. The operator then determines the quantities that each generator must produce to meet an inelastic demand at the lowest possible cost. Some results are established that allow computing the Nash equilibria of this model and some of their properties are described, such as existence conditions.