On L 1-consistency of kernel-type density estimator for stationary markov processes

A convergence result for kernel type density estimators, proved by Devroye and Gyrofi (1985), is extended to stationary Markov processess satisfying (G ₂-condition introduced by Rosenblatt (1970).     

Some characteristics of moral problems in evaluation practice

In order to understand better the nature of moral problems in evaluation, an actual incident from evaluation practice is examined. Based on the incident, six characteristics of moral problems are identified and briefly discussed. The types of research needed on moral aspects of evaluation practice are presented, and ways in which the evaluation profession can aid practitioners in dealing with moral problems are outlined.     

广义数学期望

本文应用 H.L.P.均值于样本,构造了广义样本均值;为了将它用于参数估计,根据替换法则(Substitution rule),推广了数学期望的定义,同时引入新的无偏性.最后应用广义数学期望的基本性质推出若干结论(定理1～4),说明在参数估计方面应用广义均值是有意义的.     

Insuring equity in compensatory education student selection

Student selection strategies, because they determine who will receive special services, must be evaluated in terms of equity and validity. Yet those responsible for designing compensatory education student selection in the local school district lack methods that allow them to appraise their selection strategies in terms of equity. This paper describes a decision-theory-based procedure that, if followed, will increase the informational value of data often available from program evaluation data collection and district information systems. The information produced by the decision theory approach bears directly on the basic question of who gets served.     

L1-Tightness and the law of large numbers in D(IR)

This article presents laws of large numbers for random elements of D(IR). The proofs bring forth the similarities between processes restricted to compact sets of D (IR) and processes with increasing trajectories. The results appear to generalize existing results and cover the independent identically distributed case studied by Ranga Rao.     

Corporate support mechanisms for families: An exploratory study and agenda for research and evaluation

Based on telephone interviews with representatives from 16 corporations in the Baltimore-Washington area, this article explores the awareness of corporate officers of the linkages between work and family systems, their perceived responsibility for implementing policies and services that lend support to the family circumstances of employees, and the types of actions they had initiated in their corporations to help employees better balance work and family demands. Study results demonstrate limited awareness among corporate officers toward the work and family interface, employer uncertainty about corporate responsibilities for the family situation and demands of employees, and limited corporate development of family-oriented policies and services. These results are discussed in the context of recent federal initiatives to encourage greater corporate response to the family circumstances of employees. Implications are suggested for further research and evaluation.     

从二语词汇习得的心理表征与发展看词汇僵化现象的成因

中国英语学习者(并列双语者)二语词汇知识的内部结构由词目和词位组成。二语词汇的心理表征和发展分为三个阶段:形式阶段、母语词目中介阶段和整合阶段。并列双语者在达到第二阶段后出现词汇僵化现象,其主要原因在于母语词目信息占据了二语词目空间,二语词目知识被挡在二语词条知识之外,无法实现全面合理有效的整合。因此,二语词条的发展不能自然地过渡到整合阶段,致使二语词汇知识无法变成词汇能力。解除词汇僵化的有效途径是,在中高级二语学习阶段尽量避免母语中介作用和翻译法,采用语境法习得语义。这样,二语形式与二语语义或概念之间可建立直接紧密的联系,认知型词汇可发展成活用型词汇。     

MATERIALS PRICES AND PRODUCTIVITY

There is substantial within‐industry variation in the prices that plants pay for their material inputs. Using plant‐level data from the US Census Bureau, I explore the consequences and sources of this variation in materials prices. For a sample of industries with relatively homogeneous products, the standard deviation of plant‐level productivity would be 7% smaller if all plants faced the same materials prices. Moreover, plant‐level materials prices are persistent, spatially correlated, and positively associated with the probability of exit. The contribution of entry and exit to aggregate productivity growth is smaller for productivity measures that are purged of materials price variation. After documenting these patterns, I discuss three potential sources of materials price variation: geography, differences in suppliers' marginal costs, and within‐supplier markup differences. Together, these variables explain 15% of the variation of materials prices.     

BUILDING REPUTATION FOR CONTRACT RENEWAL: IMPLICATIONS FOR PERFORMANCE DYNAMICS AND CONTRACT DURATION

We study how career concerns affect the dynamics of incentives in a multi‐period contract, when the agent's productivity is a stochastic function of his past productivity and investment. We show that incentives are stronger and performance is higher when the contract approaches its expiry date. Contrary to common wisdom, long‐term contracts may strengthen reputational effects whereas short‐term contracting may be optimal when investment has persistent, long‐term effects.