影子价格两种定义的统一性及其经济学含义

通过应用库恩-塔克定理,本文论证了线性规划对偶解和一般数学规划的拉格朗日乘子这两种影子价格定义的统一性。由于非线性规划比线性规划更具有普遍性,本文的结论为深入讨论影子价格的经济学意义提供了极大方便。完全竞争是影子价格等于机会成本和市场价格的充分条件。但在不完全竞争条件下,影子价格一般不等于机会成本和市场价格,也不代表资源的最优配置价格,它反映的只是企业的资源利用效率。     

峰荷需求、资本配置效率与中国网络型基础产业投融资机制改革——对阿弗奇-约翰逊模型的一个扩展

阿弗奇—约翰逊模型(A—J模型)表明规制对象具有过度使用资本倾向,相应的实证检验中同时存在肯定和否定的结果,但基本的A—J模型、已有扩展和实证检验都忽略了受规制行业的峰荷需求特征。本文从基本的A—J模型出发,假定生产要素单位使用成本与规制机构所认可的单位核算成本不同,考察了峰荷需求特征下受规制网络型基础产业的投资行为,提供了资本配置效率的衡量标准。本文的基本结论在于,峰荷需求条件下受规制企业不一定投资过多,这也解释了为何A—J效应的实证检验存在相互矛盾的结果。     

马铃薯在中国传播的技术及社会经济分析

本文从生物、技术及社会经济的角度考证马铃薯在中国传播的过程，重点对传播条件和传播障碍进行阐述，分析了20世纪中国的社会变迁和科技进步对马铃薯传播的影响，并进一步讨论马铃薯扩种对我国粮食生产和社会生活的作用。     

关于增加湖北省中等收入者比重的调查与分析(下)

我国中等收入阶层的形成和壮大，是同无数中等收入的形成和壮大联系在一起的，也与我国经济社会体制的不断跃迁、不断完善密切相关，特别是中等收入的特质及其影响力，是与我国经济社会体制改革的效率和整个社会的福利水平呈现一种正相关关系的。扩大中等收入比重，提高低收入收入水平，这是在新的历史条件下对我国传统收入分配制度的一个新的注解。     

Efficient Markets Hypothesis and the Emerging Capital Market in Sri Lanka: Evidence from the Colombo Stock Exchange – A Note

The behaviour of stock prices on the Colombo Stock Exchange (CSE) is examined with a view to determine its consistency with the weak form of the Efficient Markets Hypothesis (EMH). Runs, Autocorrelation and Cointegration tests are applied to daily, weekly and monthly CSE index data for the period of January 1991–November 1996. Results of Runs, Correlation and Cointegration tests overwhelmingly reject the serial independence hypothesis, leading to the conclusion that the behaviour of stock prices in the Colombo Stock Exchange is not consistent with the weak form of the Efficient Markets Hypothesis. Tests of the-day-of-the-week-effect, however, show that there is no evidence of such a phenomenon on the Colombo Stock Exchange stock prices. Results of the tests of the-month-of-the-year-effect lead to the conclusion that CSE prices do not display any month-specific behaviour.     

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.     

Are Housing Price Cycles Driven by Irrational Expectations?

This paper investigates the extent to which condominium apartment prices are set in an efficient asset market. Unlike previous work that focuses on the time-series properties of measures of excess returns, the analysis is framed in terms of the changes in observable house prices over time. More precisely, the paper develops and applies a test of the joint null hypothesis of rational expectations, perfect markets, and no risk premium in the Vancouver condominium apartment market. The empirical results provide significant evidence against the joint null hypothesis. On average, ex post house price changes move in a direction opposite to their rational expectation. This approach offers a methodological advantage over the standard efficiency literature and is shown to provide a more powerful test of market efficiency than conventional return regressions. Another contribution of the paper is to characterize the time-series properties of deviations of condominium prices from those predicted by the risk-neutral rational expectations model, using cointegration and random coefficients techniques. Deviations in house price changes from their (risk-neutral) rational expectations are time varying, stationary, and related to the stage of the real estate price cycle.     

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.     

纯氧曝气的研究进展

介绍了纯氧曝气的生化机理、应用领域、供氧方式、污泥性能等以及它与普通空气曝气相比在技术、经济方面显示出的优越性。随着纯氧曝气的发展和国家新标准增加了脱氮除磷方面的排放要求，使得纯氧曝气在城市污水处理老厂的改造和新厂的建设中具有很好的前昔。