日本政府自1996年實施金融大改革(Big Bang)，金融市場從保守走向自由開放，面對競爭越趨激烈的環境，日本產險業開始出現公司併購重組的情形，使得市場越趨集中。無論是市場結構的改變，或是併購亦可能對公司既行營運模式造成改變，進而影響公司的經營效率，都可能對公司的市場壟斷力造成影響，進而影響市場的競爭度。本研究以2001-2012年日本產險市場為研究對象，主要目的在探討市場集中度及公司效率此兩種變數是否會對競爭度產生影響。實證模型採用追蹤資料固定效果模型作分析，並以Lerner指數作為衡量公司市場壟斷力的變數，赫芬達指數作為衡量市場集中度變數，以資料包絡分析法所求出之效率值代表效率變數。實證結果發現，市場集中度對於公司的市場壟斷力無顯著影響，而產險公司效率與公司的壟斷力呈正向關係，當公司效率越高，其壟斷力越高，而市場競爭程度越低。 / Since the Japanese financial system reform, “Big Bang,” was commenced in 1996, the financial market in Japan has been transformed into free and open market. At the same time, the Japanese insurance market became more competitive due to the regulatory changes. Many mergers and acquisitions appeared in Japanese insurance industry and that increased the market concentration. The reform has also changed firm operation modes and then have impact on firm efficiency. Furthermore, the changes of market structure and firm efficiency may have impact on market power and therefore affect the level of competition. The objective of this study is to assess the impact of concentration and efficiency on competition in Japanese property-liability insurance industry using the fixed effect model. The research period is from 2001 to 2012. This study utilizes Lerner index to measure market power (competition) and Herfindahl-Hirschman index (HHI) to measure market concentration. And the data envelopment analysis (DEA) method is applied to evaluate the efficiency of insurance companies. The results show that the relation between concentration and competition is not significant. This paper also finds evidence that higher firm efficiency leads to higher market power (lower competition).

This paper analyses the competitiveness in the banking sector of eight countries in the SADC region. Both the Panzar-Rosse and the Lerner Index approaches were used for the period 2002- 2013. Although the results yield opposing outcomes, the overall findings suggest that the eight countries cannot be described as being perfectly competitive but rather suggest imperfect competition in these banking sectors. These countries could be characterised as monopolies when using the Panzar-Rosse study and monopolistically competitive when using the Lerner Index.

Eastern European countries have experienced many political upheavals and economic reforms since their declaration of independence of the U.S.S.R. Our study is intended for a series of estimations concerning the market structure of the banking in the Eastern European countries. Besides, we also attempt to assess the transformation of the competitive conditions of the banking industries in these countries. We employ three different methods for the assessment: The Panzar-Rosse Model, the Lerner index and the structural indicators (Concentration Ratio and HHI). We also use quantile regression to estimate the change of the H statistics corresponding to different deciles of the bank revenues beside the standard regression. The estimation results of the H statistics and the Lerner indice both indicate the banking markets of the Eastern European countries are characterized as monopolistic competition. Profitable banks in some countries face keener competition in the market. Besides, the Lerner index is affected by some variables, and tends to show the consistent estimation results with the H statistic in general. On the other hand, the structural indicators reveal a descending concentration in most Eastern European countries. However, the comparison between structural and non-structural methods does not support the general view that concentration undermines competition.

Yes / The traditional Lerner index is limited in its capacity to estimate the level of competition in the economic sector from the perspective that it mainly focuses on the overall level of market power for each individual decision-making unit. Recently, Fukuyama and Tan (J Oper Res Soc, 73:445–453, 2022) estimated the Lerner index by applying the nonparametric data envelopment analysis (DEA) to calculate the marginal cost, which is an important component in the estimation of the Lerner index. Our study further extends the study of Fukuyama and Tan (J Oper Res Soc, 73:445–453, 2022) by estimating the marginal cost under the DEA in a multi-product setting. Our proposed methodology benefits from the ability to find positive marginal costs for all the products and specifies all decision-making units are profit maximizers. In order to achieve this, the marginal cost is estimated by referring to the nearest point on the best practice cost-efficient frontier for the profit-maximizing firms. We then apply our innovative method to the Chinese real estate industry. The result shows that the Chinese real estate industry has higher market power in the residential commodity housing market than that in the commodity housing market. This is also the case for different geographical areas in China. Overall, for both of these two different markets, the level of market power experiences a level of volatility.

The first essay compares six common models, linear, quadratic, Cobb-Douglas, translog, logarithmic, and transcendental, to estimate wheat yield and area functions for Saudi Arabia. Data cover 1990-2016 for all the variables that affect wheat supply. After testing the models using Box-Cox, multicollinearity, and autocorrelation tests, we decide that the Cobb-Douglas models provide the best fit for both yield and area. We find the price elasticity of wheat is inelastic. Yield price elasticities are more inelastic than area elasticities. The impact of government policy number 335 has a larger effect on area than yield. The cultivated area of wheat, the one-year lag of yield, and the number of machines per hectare are the most influential factors affecting wheat yield. The primary factors influencing the area models are a one-year lag of both cultivated area and yield, as well as the number of machines per hectare. The second essay estimates the residual demand elasticity that rice exporters face in Saudi Arabia. The inverse residual demand methods, as proposed by Reed and Saghaian 2004, are used for rice exporters to Saudi Arabia during the period 1993-2014. Estimation results of the elasticities of the residual demand indicate that Australia, India, and Pakistan enjoy market power, while Egypt faces a perfectly elastic demand curve. We find Thailand and the US had positive inverse residual demand which means they also have no market power. The last essay is about the virtual water trade in Saudi Arabia. Using the concept of virtual water introduced by Allan 1994 and developed by Hoekstra and Hung (2002), we estimate virtual water trade for 20 crops of Saudi Arabia during 2000-2016. Our result shows the average virtual water trade was 12.5 billion m3/year. Saudi has net virtual water imports, with the most significant virtual water imports coming from cereals & alfalfa and vegetables; and there is net virtual water export of fruit. Saudi virtual water trade reduces pressure on water resources by 52%. Distance plays a role in Saudi virtual water export; we found that more than 90% of exports go to neighboring countries, including 45% to GCC countries. More than 30% of virtual water imports come from Europe. A Gravity model is used to investigate whether water scarcity variables influence trade. We compare the OLS, Fixed effects, Random effects, and PPML estimators to get the best model. The AIC, and tests for multicollinearity, and heteroskedasticity assist in determining estimation procedures and the final models. We cluster the errors by distance to improve the specific country effect variables such as economic mass variables. For the cereals and alfalfa group, we find that water-related variables influence virtual water imports of cereals, millet, sorghum, corn, barley, and sesame. Therefore, we suggest that a basic gravity model be applied to the other crops. In the vegetable group, we find that related water variables impact virtual water trade for all crops except marrow. Dates are the only fruit crop that are not influenced by the water-related variables.

本文主要進行東亞十國競爭程度分析，研究期間為1994年到2008年，除比較各國差異外，也分析東亞各國在歷經亞洲金融風暴洗禮前後的差異。本研究使用非結構法之Panzar & Rosse檢定法為主軸，並採用較新的分量迴歸模型，從而推論在不同分量上的市場競爭型態，再與結構性指標CR4和HHI結果做比較，另外再採用近年來文獻也常提及的Lerner index方法，作為競爭度變數，探討銀行集中度和銀行效率對市場競爭的影響。發現東亞各國銀行業競爭程度為高，且在經歷亞洲金融風暴前後皆為獨占性競爭。 / This paper investigates the degree of market power in the East Asia banking systems during the years of 1994–2008 using the ‘H-statistic’ by Panzar and Rosse , uses quantile regression to analyze the information between the standardized total revenue and the H-statistic , compares the result with concentration k-bank concentration ratio (CRk) and Herfindahl–Hirschman Index (HHI) , and presents an empirical study on the impact of bank concentration and bak efficiency on bank competition by using the Lerner index. This paper finds that banks in the East Asia operate under monopolistic competition before and after the Asian Financial Crisis.

The aim of this paper is to analyze the strategic behavior of the leading firms on the Swedish wholesale electricity market. This thesis wishes to address the competition situation on the market and how the firms can manipulate the price in order to maximize the profits. The Swedish electricity market was deregulated in 1996 and the predicted outcome was that the competition on the market would increase. However, today’s market is highly vertically integrated with three dominating firms; Vattenfall, E.ON, and Fortum. Moreover, the market has similar characteristics of an oligopoly with high entry barriers, limited room for product differentiation, and limited access of information. The Herfindahl-Hirschman Index and the Lerner Index show that the wholesale electricity market is highly concentrated and that market power exists. Besides external factors that affect the electricity price, such as emission trading and the amount of water in the reservoirs, the leading firms can with their market power manipulate the price. This can be done by preventing new entrants to enter the market which has led to underinvestment in new capacity with lower production costs.

<p>The aim of this paper is to analyze the strategic behavior of the leading firms on the Swedish wholesale electricity market. This thesis wishes to address the competition situation on the market and how the firms can manipulate the price in order to maximize the profits.</p><p>The Swedish electricity market was deregulated in 1996 and the predicted outcome was that the competition on the market would increase. However, today’s market is highly vertically integrated with three dominating firms; Vattenfall, E.ON, and Fortum. Moreover, the market has similar characteristics of an oligopoly with high entry barriers, limited room for product differentiation, and limited access of information.</p><p>The Herfindahl-Hirschman Index and the Lerner Index show that the wholesale electricity market is highly concentrated and that market power exists.</p><p>Besides external factors that affect the electricity price, such as emission trading and the amount of water in the reservoirs, the leading firms can with their market power manipulate the price. This can be done by preventing new entrants to enter the market which has led to underinvestment in new capacity with lower production costs.</p>

Yes / This study estimates output market power in the Chinese banking industry using the multi-output Lerner index. We propose a minimum distance cost function approach, which allows us to determine not only the level of market power but also the non-profit maximizers and efficiency level of Chinese banks. Following the first-stage analysis, we employ the generalized method of moment system estimator to evaluate the impacts of bank innovation and trade openness on market power in a multi-output banking context. In particular, we innovatively propose a causal structure analysis based on Wang and Blei (2019) to validate and verify the robustness of our results. We also assess this relationship for different types of bank ownership in China. The findings suggest that Chinese banks exhibit high market power in loans. Furthermore, the results show that bank innovation and trade openness have a significant negative impact on market power in loans, but a significant positive impact on market power in securities. The results also indicate a significantly negative impact of trade openness on overall market power. We find that higher levels of innovation among state-owned and joint-stock commercial banks improve the overall level of market power. The results suggest that, for all bank ownership types, trade openness has a significant negative impact on market power in loans but a significant positive impact on market power in securities. The impact on the overall level of market power is consistently significant and negative. / The full-text of this article will be released for public view at the end of the publisher embargo on 11 Aug 2025.

The aim of this study is to analyze the relationship between competition and loan portfolio quality in the Peruvian microfinance sector. To make this analysis the market is segmented into three groups of microfinance microfinance institutions IMFs), considering the average volume of its loans. So that, in the first group (large IMFs) entities of higher average volume of loans are located, in the second group (medium IMFs) entities with an average volume of loans are located and finally, in the third group (small IMFs) are entities with lower average loan volumes.This segmentation reflects the heterogeneity of size for loans between IMFs. The results show the Lerner index decreasing over time, for both the group of large IMFs and the group of small IMFs, showing a decrease of market power and increased competition in these two groups of entities. In the group of medium IMFs behavior Lerner index shows a growing trend in the last months of the period studied thus indicating a greater market power and less competition in this group of microfinance operators. On the other hand, an inverse relationship between the Lerner index over delinquency rate in the three groups of IMFs is found, implying that increased competition in the Peruvian microfinance market has deteriorated the quality of loan portfolio the period analyzed. This result is obtained by controlling the behavior of other important variables to explain the delinquency rate such as the business cycle, credit expansion, efficiency and profitability of institutions, and the effect of the international financial crisis of 2008. / El objetivo de este estudio es analizar la relación que existe entre la competencia y la calidad de cartera en el sector microfinanciero peruano en el periodo 2003-2015. Como indicador de competencia se emplea el poder de mercado estimado por el Índice de Lerner y como indicador de calidad de cartera se utiliza la tasa de morosidad. El análisis segmenta el mercado microfinanciero en tres grupos de instituciones microfinancieras (IMF), considerando el volumen promedio de sus colocaciones, de manera que, en el primer grupo se ubican las entidades con un mayor volumen promedio de colocaciones, en el segundo grupo se encuentran las entidades con un volumenmedio de colocaciones y finalmente, en el tercer grupo se ubican las entidades con menor volumen promedio de colocaciones. Esta segmentación refleja la heterogeneidad de tamaño que existe entre estas entidades. Los resultados muestran un Índice de Lerner decreciente, para el primer y el tercer grupo, evidenciando una mayor competencia. En el segundo grupo, el comportamientodel Índice de Lerner muestra una tendencia creciente en los últimos meses del periodo estudiado, reflejando una menor competencia. Por otro lado, se evidencia una relación inversa entre el Índice de Lerner y la morosidad en los tres grupos, lo que implica que el aumento de competencia en el mercado microfinanciero ha generado un deterioro en la calidad de cartera crediticia. Esteresultado se obtiene controlando el comportamiento de otras variables como son: el ciclo económico, la expansión de los créditos, la eficiencia y la rentabilidad de las instituciones, además del efecto de la crisis financiera internacional del 2008.