Strong laws of large numbers for dependent heterogeneous processes: a synthesis of recent and new results

This paper surveys recent developments in the strong law of large numbers for dependent heterogeneous processes. We prove a generalised version of a recent strong law for Lz-mixingales, and also a new strong law for Lpmixingales. These results greatly relax the dependence and heterogeneity conditions relative to those currently cited, and introduce explicit trade-offs between dependence and heterogeneity. The results are applied to proving strong laws for near-epoch dependent functions of mixing processes. We contrast several methods for obtaining these results, including mapping directly to the mixingale properties, and applying a truncation argument.     

Global imbalances and household savings: The role of wealth

Many claim that fluctuations in U.S. private savings help to create and to sustain global imbalances because of their influence on the current account deficit. To test this claim, this paper investigates the determinants of aggregate household savings using a panel of 18 developed countries for the period 1980–2005. We weave two strands of literature: the first strand from consumer theory, considering specifically the ‘wealth effect’, the second strand from aggregate private savings theory. The original contribution of this paper derives from the main explanatory variables of the household savings function: two measures of household wealth, the first a financial variable and the second a variable for tangible/housing stock. The salience of these variables has not been tested before. The model is then enriched with variables taken from the private savings literature. To find the best technique to estimate the long run savings function, unit root and cointegration tests are carried out, from which evidence of a cointegrating relationship is found. The group means FMOLS is used to estimate the model. The empirical evidence suggests effects consistent with theory: an increase in wealth negatively affects household savings. Furthermore, when important explanatory variables, such as government savings and population dependency ratios, are included in the model, tangible wealth becomes the only kind of wealth to (weakly and negatively) influence household savings in developed countries. In the U.S. however, wealth does not seem to affect household savings negatively, it seems instead that government savings and population changes better explain the decline of savings during the past two decades. This finding provides additional evidence on the issue of global imbalances, and suggests that the recent booms of the stock and the real estate markets should not be blamed for the decline in U.S. household and private savings.     

基于C／S的煤矿生产调度信息管理系统开发与应用

煤矿生产调度是煤矿企业管理中安全生产的指挥中心，对煤矿的安全生产起到了至关重要的作用。在已建成的网络平台的基础上，开发基于C／S模式的煤矿调度管理信息系统（MIS），结合计算机网络技术、数据库技术和信息管理技术，实现矿级调度与集团总调度数据通信、信息资源共享和管理。     

Quadratic estimation in mixed linear models with two variance components

Explicit expressions for Bayes invariant quadratic estimates, biased and unbiased, are presented and proved to cover the entire class of admissible estimates in the considered classes. An unbalanced genetic model is studied for demonstration.     

Food security, consumption diversification and foreign exchange balances in Indonesia: Results from a multi-commodity simulation

Many countries adopt economic development strategies, within which an important element is the maintenance of low and stable food prices. In Indonesia, this is achieved principally through government subsidies to consumers of imported rice, the total cost of which fluctuates considerably from year to year, depending on world price movements and domestic production performance. Higher and possibly less stable domestic food prices appear inevitable in Indonesia, however, as the spectre of reduced oil revenues increases the government's concern with the cost of its food policy. Results from a stochastic simulation model of the agricultural sector show that the food price risk to which consumers and producers would be exposed in the absence of the stabilizing component of Indonesia's food policy would be considerable, rendering this component an unlikely area for significant change. A viable policy option appears to be the continuance of rice and wheat price stabilization, but with a graduated increase in the relative price of rice, reaching a total of 10% by 1985. Such a policy could result in net self-sufficiency in foreign exchange from staple food trade by 1990 and an improvement in aggregate economic surplus, although the expected decade improvement in food-energy consumption per capita would fall from 10% to 8%.     

Have the relative employment prospects for the low-skilled deteriorated after all?

Has the relative unemployment propensity for the low-skilled increased during the 1990s? We address this question empirically, based on two notions of low skills; i) low education, and ii) low ability, conditioned on education and work experience. Ability is identified by previous earnings. Evaluated by the education-based measure, we find that unemployment propensity has not developed unfavourably for the low-skilled. Evaluated by the ability-based measure, it has. We uncover a steady deterioration of employment prospects for persons with low ability relative to others with similar formal qualifications. The adverse employment effects of being low-skilled are stronger the higher is formal education.All correspondence to Knut Røed. The paper is part of the project Sorting, exposed groups and labour market programs financed by the Research Council of Norway. We wish to thank Rolf Aaberge, Paul Gertler, Harald Goldstein, Karl Ove Moene, Jon Strand, Steinar Strøm, Asbjrn Rødseth and an anonymous referee for helpful comments. Responsible editor: John F. Ermisch.     

Inferences concerning interpersonal choices given anonymously

It may be difficult or impossible to make a reliable empirical investigation of an unknown network of interpersonal choices or contacts if these are in some respect sensitive for the individuals involved. We consider how choice data given anonymously can be used to reveal various features of the network. Using tools from statistical decision theory and information theory we can determine risks and capacities of disclosing choice data, the graph structure of choice data and its numbers of loops and mutuals. We give some general results, illustrate the combinatorial complexity of the problem and comment upon the computational difficulties.     

The goal-oriented approach to evaluation: Critique and case study from drug abuse treatment

The specification and measurement of program goals remains central to most evaluation research strategies, yet procedures for implementing this approach are not well-articulated. It is the purpose of this discussion to describe a stepwise procedure for programmatic goal setting and monitoring used in a demonstration drug treatment program for women. Three implementation steps are described: (a) goal setting, (b) checking for consistency, (c) monitoring and feedback. The advantages and limitations of this approach are discussed and useful complementary measurement strategies are suggested.     

Projective (2n,n,λ,1)-designs

A projective (2n,n,λ,1)-design is a set $\text{D}$ of n element subsets (called blocks) of a 2n-element set V having the properties that each element of V is a member of λ blocks and every two blocks have a non-empty intersection. This paper establishes existence and non-existence results for various projective (2n,n,λ,1)-designs and their subdesigns.     

Procedures for improving the mle for ordered binomial parameters

The problem is that of estimating the probabilities of m independent binomial random variables when their probabilities are known to be nondecreasing and the loss function is squared error. In the cases where the m.l.e. is inadmissible (essentially when the total number of trials is 7 or more) we present a method for modifying the m.l.e. to get a better estimator. The method requires a series of changes. At each step we alter the action taken by the m.l.e. on each of three, appropriately chosen, points in the sample space.