Effects of repetition and consistency of personalization treatments on response rate in mail surveys

One unequivocal finding of past research has been that follow-ups improve response rates in mail surveys. Several ways to construct sophisticated data collection systems using follow-ups in combination with other response-improving techniques are discussed, giving rise to the issue of whether repetition of techniques in each follow-up is more effective than single use in the first mailing. Two experiments were conducted to examine the effects of repeated versus single implementation of personalization of the outside envelope. A consistent use of personalization procedures in each mailing obtained a higher response rate than an inconsistent one, consisting of personalization of the first mailing with impersonal follow-ups. A second experiment showed repeated personalization to be more effective than repeated impersonal mailings.     

Log linear models for multivariate paired comparison experiments with ties

A log linear multivariate paired comparison model for ties is proposed in which the cell probabilities under independence are those given by Davidson (1970). Altham's (1970) generalized measure of association (iv) is used to compare the association structure between two models, one having full, the other having reduced association structure. Based on the model with reduced association structure, the analysis of data from a consumer preference experiment is presented.     

A cost-benefit analysis of a smoking cessation program

Smoking cessation programs are usually evaluated in terms of the percentage of participants who have stopped smoking at least 6 months after the program's completion. This paper shows how a relatively low rate of behavior change may actually result in a high ratio of benefits to costs. Cost-benefit analysis is done for a specific program but the procedures and cost estimates are generalizable to other smoking cessation programs. Benefits to the firm included reduced costs of insurance and the savings due to employee absenteeism and disability. Costs included the program costs as well as the opportunity costs of the participants. Data from the literature and from the specific program are combined to form conclusions about the effectiveness of the program.     

用Struts实现MVC结构

简要介绍了Struts的概念及其构成，在此基础上用实例阐述了如何用Struts实现MVC结构．     

Job Creation and Destruction over the Business Cycles and the Impact on Individual Job Flows in Denmark 1980-2001*

Summary: Job creation and destruction should be considered as key success or failure criteria of the economic policy. Job creation and destruction are both effects of economic policy, the degree of out- and in-sourcing, and the ability to create new ideas that can be transformed into jobs. Job creation and destruction are results of businesses attempting to maximize their economic outcome. One of the costs of this process is that employees have to move from destroyed jobs to created jobs. The development of this process probably depends on labor protection laws, habits, the educational system, and the whole UI-system. A flexible labor market ensures that scarce labor resources are used where they are most in demand. Thus, labor turnover is an essential factor in a well-functioning economy. This paper uses employer-employee data from the Danish registers of persons and workplaces to show where jobs have been destroyed and where they have been created over the last couple of business cycles. Jobs are in general destroyed and created simultaneously within each industry, but at the same time a major restructuring has taken place, so that jobs have been lost in Textile and Clothing, Manufacturing and the other “old industries”, while jobs have been created in Trade and Service industries. Out-sourcing has been one of the causes. This restructuring has caused a tremendous pressure on workers and their ability to find employment in expanding sectors. The paper shows how this has been accomplished. Especially, the paper shows what has happened to employees involved. Have they become unemployed, employed in the welfare sector or where? * First draft of this paper was presented at Deutsche Statistische Woche, Frankfurt, September 2004. Thanks to two referees for instructive comments. Financial support from The Danish Social Science Research Council through CCP is acknowledged.     

An exact formula for the mean squared error of the inverse estimator in the linear calibration problem

The linear calibration problem is considered. An exact formula for the mean squared error of the inverse estimator, involving expectations of functions of a Poisson random variable, is derived. The formula may be expressed in closed form if the number of observations in the calibration experiment is odd; for an even number of observations, the numerical evaluation of a simple integral or the use of a standard table of the confluent hypergeometric function is required. Previous expressions for the mean squared error have either been asymptotic expansions or estimates obtained by simulation.     

A set of independent sequential residuals for the multivariate regression model

In this paper a set of residuals for the multivariate linear regression model is introduced. These residuals are shown to be independent with known distributions which do not depend on the parameters of the model. Transformations of the mentioned residuals may be used to construct exact α goodness-of-fit tests for the multivariate regression model.     

On the Markov property of order statistics

The order statistics from a sample of size n≥3 from a discrete distribution form a Markov chain if and only if the parent distribution is supported by one or two points. More generally, a necessary and sufficient condition for the order statistics to form a Markov chain for (n≥3) is that there does not exist any atom x₀ of the parent distribution F satisfying F(x₀-)>0 and F(x₀)<1. To derive this result a formula for the joint distribution of order statistics is proved, which is of an interest on its own. Many exponential characterizations implicitly assume the Markov property. The corresponding putative geometric characterizations cannot then be reasonably expected to obtain. Some illustrative geometric characterizations are discussed.