Economic analysis of the impact of adopting herd health control programs on smallholder dairy farms in Central Thailand

The economic impact of adopting herd health programs for mastitis and reproduction by small-scale dairy producers of Central Thailand was assessed using a policy analysis matrix (PAM). Following a reduction in the incidence of bovine disease on adopter farms, an increase in private net profits is observed. More importantly the social costs of supporting dairy farmers is reduced; the PAM effective protection coefficient was reduced by 35% for mastitis program adopters and by 44% for reproductive program adopters, indicating improved social efficiency of dairy policy. Other indicators of efficiency and policy implications are discussed.     

Asymptotically optimal estimation of smooth functionals for interval censoring, part 1

Estimation in the interval censoring model is considered. A class of smooth functionals is introduced, of which the mean is an example. The asymptotic information lower bound for such functionals can be represented as an inner product of two functions. In case 1, i.e. one observation time per unobservable event time, both functions can be given explicitly. We mainly consider case 2, with two observation times for each unobservable event time, in the situation that the observation times can not become arbitrarily close to each other. For case 2, one of the functions in the inner product can only be given implicitly as solution to a Fredholm integral equation. We study properties of this solution and, in a sequel to this paper, prove that the nonparametric maximum likelihood estimator of the functional asymptotically reaches the information lower bound.     

From T-Bills to Stocks: Seasonal Anomalies Revisited

This paper employed eleven data series which consist of stocks, bonds, bills, equity premiums, term premiums, and various default premiums to investigate whether January seasonality reported in existing literature is robust across different states of the economy as this has important trading implications. For the periods 1926–1990, small stocks, small stock premiums, low grade bonds, and default premiums (spread between high grade, low grade and government bonds) reveal January seasonality and that the seasonality is robust across different states of the economy except for low grade bond returns and default premiums. January seasonality for low grade bond returns and low grade bond default premiums are primarily driven by results found during periods of economic expansion. Overall, January seasonality is more evident during the economic expansion periods although the magnitude of default premiums is larger during periods of economic contraction. Furthermore, prior findings of strong summer equity returns are primarily driven by the results found during the periods of economic contraction. It is also found that equity returns are generally higher during periods of economic expansion.     

The Performance of Actively Managed International Mutual Funds

International mutual funds allow individual investors to diversify abroad at a reasonable cost. This paper tests whether international funds that actively engage in country and security selection outperform passive global benchmarks. We apply a mean-variance efficiency test that incorporates the practical prohibition against short sales of open-end mutual funds. Our tests reject the efficiency of the world equity market portfolio over the sample period, and our funds as a group outperform the inefficient world index. However, we find no evidence of security selectivity ability using a 12-country benchmark. We do find that active international funds provide global diversification benefits. Tests using the Positive Period Weight (PPW) measure of Grinblatt and Titman (1989), which is robust to nonlinearity in fund and benchmark returns, yield similar results.     

On efficiency of the ratio estimator

Summary The exact mean square error for the ratio estimator of a finite population total based on simple random sampling without replacement is shown to have an expected value less than that of the variance of the ratio estimator based on Midzuno’s scheme, under a usual super-population model.     

An Average Derivative Estimation of Stochastic Frontiers

This paper utilizes the average derivative estimation of Stoker (1986) and the pesudo-likelihood estimation of Fan, Li, and Weersink (1996) to estimate a semiparametric stochastic frontier regression, y = g(x) + , where the function g(.)is unknown and is a composite error in a standard setting. The proposed semiparametric method of estimation is applied to data on farmers' credit unions in Taiwan. Empirical results show that the banking services of the farmers' credit unions is subject to economies of scale, but high degree of cost inefficiency in operation.     

The productivity of private and social farms: Multilateral Malmquist indices for Slovene dairying enterprises

Applying programming techniques to farm-level panel data for four cooperative and 12 private dairy farms in the Yugoslav Republic of Slovenia gives estimates of technical efficiency, scale efficiency, and technical progress. These are used to construct multilateral Malmquist indices of total factor productivity (TFP). For the cooperatives, TFP growth has been slow and is attributable to technical progress. For the private farms, technical progress was also slow, but TFP growth was faster due to improved efficiency. Scale inefficiency explains the poorer absolute performance of the private farms, indicating the need for land reform as well as technological change.     

H-O国际贸易理论的新兴古典分析--交易效率对国际贸易的影响

赫克歇尔一俄林的生产要素禀赋理论作为主流经济学派理论在国际贸易理论总体系中的影响力是巨大和深远的。而新兴古典贸易理论的发展，为解释国内贸易和国际贸易提供了一个统一的理论内核。这一理论的完美框架和强大的现实解释力引人瞩目。其理论的核心在于该理论独特的分析工具：超边际分析方法。采用新兴古典经济学的超边际分析法，引入交易效率，对赫克歇尔-俄林的生产要素禀赋理论进行新的分析，可以得出很多有价值的结论。     

网络经济条件下的产品内分工与模块化生产

产品内分工、模块化生产是与网络经济紧密联系在一起的，生产和供应过程不同工序、区段和环节在不同的空间完成，然后在同一个地方形成最终产品，这样的生产方式实际上就是网络经济条件下一种典型的生产方式，因而必须遵循网络经济条件下的规则，并且其本身也具有一定的规律性。本文就网络经济条件下产品内分工的根源、模块化生产的特征及作用进行了探讨，旨在加深对分工问题的认识以及获得解决一些现实经济问题的启示。     

A Stochastic Frontier Production Function with Flexible Risk Properties

This paper considers a stochastic frontier production function which has additive, heteroscedastic error structure. The model allows for negative or positive marginal production risks of inputs, as originally proposed by Just and Pope (1978). The technical efficiencies of individual firms in the sample are a function of the levels of the input variables in the stochastic frontier, in addition to the technical inefficiency effects. These are two features of the model which are not exhibited by the commonly used stochastic frontiers with multiplicative error structures.An empirical application is presented using cross-sectional data on Ethiopian peasant farmers. The null hypothesis of no technical inefficiencies of production among these farmers is accepted. Further, the flexible risk models do not fit the data on peasant farmers as well as the traditional stochastic frontier model with multiplicative error structure.