Comparisons of efficiencies between two types of DMUs : an application to Japanese public water companies

A water supply system composed of water production facilities and transmission facilities obtains water from various sources such as surface water, groundwater and so on. Although there are many empirical studies such as measuring efficiency, productivity and/or returns to scale for water supply organizations, almost all of them neglect the variety of water sources. The main purpose of this study is to compare the efficiencies of two types of DMUs (decision making units) e.g. water companies whose major source is underground vs. those whose major source is non-underground. In this study, using observations of Japanese public water companies, we will apply rank-sum-test of DEA (data envelopment analysis) approach developed by Wilcoxon-Mann-Whitney to identify whether the differences between two gropes are significant. After we examine whether two groups of DMUs have different distribution functions of efficiency, we will measure efficiencies of two gropes and compare them.

Industrial Diversity and Metropolitan Unemployment Rate

Although it has for years had a lower unemployment rate than other industrialized countries, Japan has begun to see an increase in unemployment since its economy was hit by the recession of the late 90?s. The level of a nation?s unemployment is commonly seen as a barometer of its economy?s health, so that Japan?s increased unemployment has worried the government and prompted it to consider several policy options. Unemployment rate in Japan varies by region. In general, while large metropolitan areas such as Tokyo have lower unemployment rates, smaller metropolitan areas have higher unemployment. Strangely, however, Osaka, the second largest metropolitan area after Tokyo, is suffering from a high unemployment rate. In October of 2002, the Kansai region including the Osaka metropolitan area recorded an unemployment rate of 7.2%, much higher than the average rate (5.5%). Theoretically, regional differentials of the unemployment rate are attributed to the friction resulting from adjusting for the mismatch between demand and supply of labor markets among regions. These frictional factors consist of the costs of information, moving, transactions related to housing, and psychological costs. Frictional components are important factors but are not all. Industrial structure differences also affect regional differentials of the unemployment rate. This paper investigated the relationship between unemployment rate and industrial structure in metropolitan areas, with the aim of testing the hypothesis that more industrially diversified metropolitan areas have lower unemployment rates. Previous studies have been done on the relationship between industrial diversity and unemployment rate but these do not provide concrete agreement because of the failure to control other factors affecting unemployment rate. This paper follows the theoretical justification of Simon (1988), who argues that industrial diversity attains a lower unemployment rate by assuming that the frictional component of employment fluctuations is a random variable and independent across industries. Because fluctuations are uncorrelated across industries, frictional hiring in some industries may coincide with frictional layoffs at others. Unemployed individuals can fill concurrently occurring vacancies. Therefore, the unemployment rate will be lower in the more industrially diverse metropolis. Simon?s empirical analysis of 91 large U.S. SMSAs strongly supports the hypothesis. In this study, we analyze 117 metropolitan areas in Japan for the year 1995. Because there is no authoritative definition of a metropolitan area in Japan, we began by defining metropolitan areas and collected data for each. As for a variable expressing industrial diversity, the Herfindahl index is used, which is made of both numbers of employments and numbers of firms for ten industrial classifications. Other factors used in this analysis are size of metropolitan areas, transportation conditions, unemployment insurance, average schooling length, and so on. The basic equation for the empirical analysis of the relationship between industrial diversity and metropolitan unemployment rate is as follows: Metropolitan unemployment rate = f (Herfindahl index (industrial diversity), metropolitan size, transportation conditions, unemployment insurance, average schooling length in metropolis) In addition to this analysis, we also analyze whether or not a higher location quotient shows a lower unemployment rate. In the preliminary analysis, we found there are negative relationships in almost all industries.

Comparisons of efficiencies between two types of DMUs : an application to Japanese public water companies

A water supply system composed of water production facilities and transmission facilities obtains water from various sources such as surface water, groundwater and so on. Although there are many empirical studies such as measuring efficiency, productivity and/or returns to scale for water supply organizations, almost all of them neglect the variety of water sources. The main purpose of this study is to compare the efficiencies of two types of DMUs (decision making units) e.g. water companies whose major source is underground vs. those whose major source is non-underground. In this study, using observations of Japanese public water companies, we will apply rank-sum-test of DEA (data envelopment analysis) approach developed by Wilcoxon-Mann-Whitney to identify whether the differences between two gropes are significant. After we examine whether two groups of DMUs have different distribution functions of efficiency, we will measure efficiencies of two gropes and compare them

An Analysis of the Effects of the Compact City on Economic Activities in Japan

The main purpose of this paper is to evaluate how the form and urban policies of ga compact cityh affect its economic activities. In general, bigger cities have more advantages such as agglomeration economies, but too-big cities have the disadvantages of external diseconomies such as environmental pollution and traffic congestion. Therefore, governments of industrial countries have an interest in promoting compact cities, but empirical evidence regarding how the formation and policies of compact cities affect economic activities is unclear or undocumented. In order to investigate our research question, we will conduct an empirical analysis using data from Japanese cities. As there is no official definition in Japan, we first define metropolitan areas and create a data set of 269 metropolitan areas in Japan for the year 2000. Then we estimate citiesf urban economic models by using econometric techniques. These urban economic models consist of four sections: 1) a compact city section, 2) a labor section, 3) a production section, and 4) a population section. First, the compact city section shows how the cityfs compactness measure is determined. Second, the labor section shows how the numbers of employees, the share of each industryfs employees, and so on are determined. There are 11 industries defined here, including manufacturing, public utilities, retailers, wholesalers, and so on. Third, by estimating the production function, the production section shows the extent of each industryfs economic activity in a city. The production functions estimated here are for 11 industries. Last, the population section shows how the cityfs population is determined by considering degree of economic activities, amenities, and so on. After we estimate several formulas regarding the above issues, we will conduct simulations in order to evaluate how the degree of a cityfs compactness affects economic activities and number of employees in a city. We are also able to determine what kind of factors affect the degree of a cityfs compactness. These empirical results may also be useful in determining policy aimed a achieving a sustainable city size

Industrial Diversity and Metropolitan Unemployment Rate

Although it has for years had a lower unemployment rate than other industrialized countries, Japan has begun to see an increase in unemployment since its economy was hit by the recession of the late 90's. The level of a nation's unemployment is commonly seen as a barometer of its economy's health, so that Japan's increased unemployment has worried the government and prompted it to consider several policy options. Unemployment rate in Japan varies by region. In general, while large metropolitan areas such as Tokyo have lower unemployment rates, smaller metropolitan areas have higher unemployment. Strangely, however, Osaka, the second largest metropolitan area after Tokyo, is suffering from a high unemployment rate. In October of 2002, the Kansai region including the Osaka metropolitan area recorded an unemployment rate of 7.2%, much higher than the average rate (5.5%). Theoretically, regional differentials of the unemployment rate are attributed to the friction resulting from adjusting for the mismatch between demand and supply of labor markets among regions. These frictional factors consist of the costs of information, moving, transactions related to housing, and psychological costs. Frictional components are important factors but are not all. Industrial structure differences also affect regional differentials of the unemployment rate. This paper investigated the relationship between unemployment rate and industrial structure in metropolitan areas, with the aim of testing the hypothesis that more industrially diversified metropolitan areas have lower unemployment rates. Previous studies have been done on the relationship between industrial diversity and unemployment rate but these do not provide concrete agreement because of the failure to control other factors affecting unemployment rate. This paper follows the theoretical justification of Simon (1988), who argues that industrial diversity attains a lower unemployment rate by assuming that the frictional component of employment fluctuations is a random variable and independent across industries. Because fluctuations are uncorrelated across industries, frictional hiring in some industries may coincide with frictional layoffs at others. Unemployed individuals can fill concurrently occurring vacancies. Therefore, the unemployment rate will be lower in the more industrially diverse metropolis. Simon's empirical analysis of 91 large U.S. SMSAs strongly supports the hypothesis. In this study, we analyze 117 metropolitan areas in Japan for the year 1995. Because there is no authoritative definition of a metropolitan area in Japan, we began by defining metropolitan areas and collected data for each. As for a variable expressing industrial diversity, the Herfindahl index is used, which is made of both numbers of employments and numbers of firms for ten industrial classifications. Other factors used in this analysis are size of metropolitan areas, transportation conditions, unemployment insurance, average schooling length, and so on. The basic equation for the empirical analysis of the relationship between industrial diversity and metropolitan unemployment rate is as follows: Metropolitan unemployment rate = f (Herfindahl index (industrial diversity), metropolitan size, transportation conditions, unemployment insurance, average schooling length in metropolis) In addition to this analysis, we also analyze whether or not a higher location quotient shows a lower unemployment rate. In the preliminary analysis, we found there are negative relationships in almost all industries

Doppler echocardiographic evaluation of Bjork-Shiley and St. Jude Medical prostheses in the mitral position.

The left ventricular studies by Doppler echocardiography were performed in 50 patients with a Bjork-Shiley (B-S) mitral valve and 50 patients after implantation of a St. Jude Medical (SJM) mitral valve; the effect of valve replacement on the hemodynamic performance at rest and during bicycle exercise was determined from serial echocardiographic data. Twenty-eight patients (56%) of the B-S group and 42 patients (84%) of the SJM group showed a good response to the exercise. There was no significant difference in the effective orifice area at rest among each sizes of the B-S valve. In the SJM valve, on the contrary, the effective valve orifice area increases in parallel to the size of the SJM valve. There was a clear relation between the valve size and pressure gradient. The pressure gradient directly depends on the valve size and the effective orifice area in the SJM valve. High pressure gradient group in both prostheses had a tendency to take negative values of percent increase in stroke volume. Further, there were no cases showing positive values of percent increase in end-diastolic volume among the patients whose pressure gradients were assumed to be more than 10 mmHg at rest. It is suggested that impairment of inflow caused by the artificial valve, prosthetic valve stenosis, is possibly a significant factor causing left ventricular dysfunction, notably a decrease in stroke volume during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)</p

Innovative Treatment of a Fetal Lung Mass Model Using High-intensity Focused Ultrasound (HIFU)

Current therapy for space-occupying fetal lung mass lesions (fetal pulmonary lobectomy) is invasive and technically demanding. Accordingly, new therapeutic procedures are required which are much less invasive and more efficient. The purpose of this study was to investigate the feasibility of high-intensity focused ultrasound (HIFU) as a new therapeutic modality for fetal lung mass lesions, using an experimental animal model. We created a solid fetal lung model by differential lung ventilation using anesthetized adult rabbits. In this model, experimental animals with a unilateral independent (fluid-filled) lung were maintained by single lung ventilation of the other dependent lung. Within the independent lung, target blood vessels depicted by color flow Doppler were repeatedly irradiated with HIFU energy beams (n=19). Occlusion of these blood vessels in vivo was confirmed by evaluation of the flow using color flow Doppler. After the procedure, the animals were sacrificed and their harvested lungs were assessed grossly and microscopically. Pulmonary blood vessels (artery and/or vein) were effectively occluded with 2 to 5 cycles of HIFU energy delivery (10.5 seconds each) with a success rate of 62.5% (arteries) and 72.7% (veins). No clear changes including tissue perforations were observed grossly on the surface of the lungs. Ultrasound-guided HIFU energy delivery seems promising for occlusion of the pulmonary blood vessels within a fluid-filled independent lung (fetal lung model). Thus in the future, HIFU irradiation could be used as a less invasive technique to occlude the feeding vessels of fetal lung mass lesions in utero