Locally minimum variance unbiased estimator in a discontinuous density function

The exact forms of the locally minimum variance unbiased estimators and their variances are given in the case of a discontinuous density function.     

Portfolio Optimization under Lower Partial Risk Measures

Portfolio management using lower partial risk (downside risk) measures is attracting more attention of practitioners in recent years. The purpose of this paper is to review important characteristics of these riskmeasures and conduct simulation using four alternative measures, lower semi-variance, lower semi-absolute deviation, first order below targetrisk and conditional value-at-risk.We will show that these risk measures are useful to control downside risk whenthe distribution of assets is non-symmetric. Further, we will propose a computational scheme to resolve the difficultyassociated with solving a large dense linear programming problems resulting from these models. We will demonstrate that this method can in fact solve problems consisting of10⁴ assets and 10⁵ scenarios within a practical amount of CPU time.     

The effect of corruption on the manufacturing sector in India

This article investigates the effects of corruption on the performance of the manufacturing sector at the state level in India. We employ conviction rates of corruption-related cases as an instrument for the extent of corruption, address the underreporting problem, and examine the impact of corruption on the gross value added per worker, total factor productivity, and capital-labor ratio of three-digit manufacturing industries in each state. Our estimation results show that corruption reduces gross value added per worker and total factor productivity. Furthermore, we show that the adverse effects of corruption are more salient in industries with smaller average firm size.     

Information in generalized method of moments estimation and entropy-based moment selection

In this paper, we make five contributions to the literature on information and entropy in generalized method of moments (GMM) estimation. First, we introduce the concept of the long run canonical correlations (LRCCs) between the true score vector and the moment function f(_vt,_θ0)$f(v_t,{\theta }_0)$ and show that they provide a metric for the information contained in the population moment condition E[f(_vt,_θ0)]=0$\mathrm{E}[f(v_t,{\theta }_0)]=0$. Second, we show that the entropy of the limiting distribution of the GMM estimator can be written in terms of these LRCCs. Third, motivated by the above results, we introduce an information criterion based on this entropy that can be used as a basis for moment selection. Fourth, we introduce the concept of nearly redundant moment conditions and use it to explore the connection between redundancy and weak identification. Fifth, we analyse the behaviour of the aforementioned entropy-based moment selection method in two scenarios of interest; these scenarios are: (i) nonlinear dynamic models where the parameter vector is identified by all the combinations of moment conditions considered; (ii) linear static models where the parameter vector may be weakly identified for some of the combinations considered. The first of these contributions rests on a generalized information equality that is proved in the paper, and may be of interest in its own right.     

Who has benefited from the health services system for the elderly in Japan?

This paper examines the demand and supply of medical services for the elderly in the health services system characterized by per-month fixed copayment and selective capitation fee scheme for outpatients with chronic diseases. The results indicate that the beneficiary, in particular the household dependent, visits a physician more frequently because the actual copayment decreases for the household dependent, but is nearly the same for the head of the household. Physicians, however, provide more services to the beneficiary partly because of the lowered copayment and partly because of the capitation fee scheme, which they will select instead of the fee-for-service scheme only when capitation is more profitable than Fee-for-Service. As a result, physicians as well as the insured benefit from the health services system.     

Equally-distributed equivalent utility,ex post egalitarianism and utilitarianism

We provide an axiomatization of expected equally-distributed equivalent-utility social welfare functions in the context of Harsanyi?s impartial observer theorem. For this family of social welfare functions, we show what additional axiom is necessary and sufficient for the observer to exhibit aversion to ex post inequality. We also relate this axiomatization to our axiomatization in a companion paper of generalized utilitarian social welfare functions. Given certain richness assumptions, the only social welfare functions that belong to both families are the utilitarian.     

Market competition,differences in technology,and productivity improvement: An empirical analysis based on Japanese manufacturing firm data

In this paper we examine empirically the effect of market competition on firm productivity improvements using data drawn from the Japanese manufacturing sector. We find that a non-linear relationship between competition and productivity growth induced by R&D activity as suggested by Aghion et al. (2005) holds for Japanese manufacturing firms. We also show that greater market competition widens technology differences across firms, and firms facing more intense competition are more productive than other firms. Our empirical results imply that productivity improvement through R&D activity depends on not only a competitive environment but also technological differences between firms.     

PROBLEMS IN EXPANDING JAPAN'S IMPORTS OF MANUFACTURES FROM DEVELOPING ECONOMIES: A SURVEY*

The Japanese economy is now the second largest market economy, with a large trade surplus. And yet, Japan's imports of manufactures have long been very low relative to its GNP, when compared with other industrial countries; its ratio of manufactured imports to GNP was in the range of 2.1–2.7% in the 1980-87 period, as compared with 8.5–10.3% for the industrial countries as a whole or 4.7-7.2% for the United States. The share of developing economies in total imports of manufactures in Japan is about the same as, if not higher than, those for most other industrial countries. If Japan's ratio of manufactured imports to GNP were to rise in the future to approach closer to those of other industrial countries, Japan's imports of manufactures from developing economies could be two to three times what they are today, even if Japan's GNP does not increase at all and the share of developing economies in Japan's manufactured imports does not increase. This paper is an attempt to probe the potential of the Japanese market for imports of manufactures from developing economies in terms of rising ratio of such imports to GNP. The paper explores the reasons why Japan's ratio is exceptionally low, on the basis of existing literature. (a) Japan's ratio of manufactured imports to GNP has remained exceptionally low compared with those for other industrial countries. (b) Japan's ratio of manufactured imports from developing economies to GNP has remained distinctly low despite the recent surge in such imports. (c) If a part of the reason for the low ratio for Japan was a market access problem as often alleged, the problem is not with formal import barriers such as tariffs and formal non-tariff barriers because these barriers in Japan are no higher than in other industrial countries. As for informal import barriers, evidence found indicates that: (i) Administrative guidance and flexibly managed competition policy, which in the past had considerable effects of limiting imports, appear to have declined-in importance, but they still have import-limiting effects in certain areas. (ii) Market access difficulties involving import procedures, product standards, testing and certification requirements, which were enormous in the past, may have also decreased in severity over the last decade, but problems in these areas persist. (iii) There are aspects of the Japanese distribution system and practice that seem to make foreign access to the Japanese market significantly more difficult than the access by Japanese exporters to the markets in other industrial countries. Distribution in Japan suffers from overregulation. (iv) Users of manufactured products in Japan are sensitive to quality, perhaps more so, on the average, than in other industrial countries. Does the recent upsurge in Japan's imports of manufactures suggest that the traditional import behavior of Japan is changing? Japan's manufactured imports measured in yen increased by 18 and 27 percent in 1987 and 1988, respectively, and those coming from developing economies increased even more rapidly. There is also some evidence that price and income elasticities of demand for manufactured imports may have increased recently. These are encouraging, but it remains to be seen whether the trends will continue far enough into the future to bring Japan's import behavior more into line with those of other industrial countries. If they do, implications for the market prospects of manufactured exports from developing economies could be far-reaching. Outstanding questions are: (i) How much of the recent increase in manufactured imports is attributable to the appreciation of the yen (price effect)? How much is attributable to the increase in income or industrial output (income effect)? How much is attributable to removal of formal and informal import barriers effected so far (structural change)? Has consumer taste changed? (ii) Why have Latin American countries not been successful in promoting their exports of manufactures to Japan, when Asian exporters have been so successful? (iii) Up until now, the share of developing economies in Japan's manufactured imports has not been particularly low compared with those for other industrial countries, but is this share likely to fall or rise in the future? (iv) What is the likely impact of recently increased direct investment (DFI) by Japanese manufacturers in developing economies on the imports of their products into Japan?     

Arthur L. Norberg. Computers and Commerce: A Study of Technology and Management at Eckert-Mauchly Computer Company, Engineering Research Associates, and Remington Rand, 1946-1957. Cambridge, Mass.: MIT Press, 2005. x + 347 pp. ISBN 0-262-14090-X, $40.00 (cloth).

Arthur Norberg’s Computers and Commerce is a much-neededstudy of the technical and business history of the Eckert-MauchlyComputer Corporation (EMCC) and Engineering Research Associates(ERA). Although there have been many historical studies aboutIBM, there have been relatively few accounts describing thefirm’s primary competitors or of the early formation ofthe industry. Norberg’s study offers valuable insightsinto the latter by providing a detailed history of the technicaldecisions and financial strategies of the two entrepreneurialfirms that