Age,Trend, and Cohort Effects in a Macro Model of Canadian Expenditure Patterns

A quadratic almost ideal demand system allowing for age, cohort, and trend effects is developed at the macro level. The model is estimated by maximum likelihood, using a three-tier iterative/search method applied to pooled 1961–1992 time series for five regions of Canada and six categories of expenditure. Hypothesis tests indicate support for the model specification. Elasticities are compared with those reported in other studies, with special attention to food. Effects of demographic and trend variables on elasticities and expenditure shares are investigated. An overall conclusion is that such effects can be very important in a macro demand system.     

Illustration Of Three-Dimensional Surfaces

With the ready availability of computer graphics packages, it is now straightforward to produce isometric projections of three-dimensional surfaces. The usefulness of such projections is shown by means of a number of examples. Illustrating likelihood surfaces and bivariate density functions.     

Dirichlet forms: Some infinite-dimensional examples

The author presents three examples of a Markov process taking values in an infinite-dimensional state space and analyzes the sample path behaviour using the theory of Dirichlet forms.     

Modelling cell generation times by using the tempered stable distribution

Summary.  We show that the family of tempered stable distributions has considerable potential for modelling cell generation time data. Several real examples illustrate how these distributions can improve on currently assumed models, including the gamma and inverse Gaussian distributions which arise as special cases. Our applications concentrate on the generation times of oligodendrocyte progenitor cells and the yeast Saccharomyces cerevisiae . Numerical inversion of the Laplace transform of the probability density function provides fast and accurate approximations to the tempered stable density, for which no closed form generally exists. We also show how the asymptotic population growth rate is easily calculated under a tempered stable model.     

监狱民营化决策的决定性因素探析

目前,有相当多的关于政府服务民营化的研究。这些研究文献深入探讨了民营化的政策,政策的局限性及存在的问题,民营化的成本,政府的责任以及公共事业管理者如何处理相关的、复杂的合同关系。相比而言,却很少有通过实践研究合同外包的决定性因素。同时,大多数文献推论:民营化决策仅仅出于政治观点和象征主义的需要,却也没有通过实践研究过民营化的动力。本文考察国家政府部门进行监狱民营化的潜在决定性因素。通过对55个州的监狱民营化数据的分析,我们发现:与那些普遍提出的监狱民营化是出于诸如节约成本等财政和经济考虑的主张相比,一个州执政者的党派与政党文化等政治因素更有可能影响民营化决策。     

A comparison of methods to obtain active parental consent for an international student survey

Many school-based research efforts require active parental consent for student participation. Maximizing rates of consent form return and agreement is an important issue, because sample representativeness may be compromised when these rates are low. This article compares two methods for obtaining active parental consent: return of consent forms in the mail versus return by students to their classrooms. The methods were tested in a pilot study of 46 schools (1,058 students), with half of the schools randomly allocated to each of the alternative methods. A hierarchical nonlinear model of consent form return and agreement rates suggests that the student-delivered method is more successful at producing higher rates of consent form return and agreement to participate in the study, after controlling for school-level characteristics. The authors discuss the findings and their implications for other researchers engaged in school-based research with adolescents.     

Selection of the Transformation Variable in the Laplace Transform Method of Estimation

The work of this paper is based on the innovative approach of Feigin et al. (1983), who estimate parameters of lifetime distributions by equating empirical and theoretical Laplace transforms. We show that the optimal choice of the transform variable depends critically upon the number of sampling times, the way they are spaced, and how the empirical transform is formed. Two new approaches for choosing the transform variable, viz. using cross-validation or constrained optimisation, are introduced and shown to have potential for wide-ranging use.     

Decreasing the Recent Immigrant Earnings Gap: The Impact of Canadian Credential Attainment

It is well documented that newly arrived immigrants face a significant earnings gap relative to native‐born workers. One way for new immigrants to improve their relative labour market position upon arrival in a host country is to improve their educational credentials. According to signalling theory, a host‐country credential should provide employers with a proxy for true productivity on the job, leading to higher earnings. Using data from a Canadian longitudinal survey, we employ longitudinal growth‐curve techniques to estimate the effect of receiving a Canadian educational credential on the income growth of racial‐minority recent immigrants compared to native‐born Canadians. The results indicate that the earnings gap between recent immigrants and native‐born Canadians is significantly reduced with the attainment of a Canadian educational credential.