A latent process model for dementia and psychometric tests

We jointly model longitudinal values of a psychometric test and diagnosis of dementia. The model is based on a continuous-time latent process representing cognitive ability. The link between the latent process and the observations is modeled in two phases. Intermediate variables are noisy observations of the latent process; scores of the psychometric test and diagnosis of dementia are obtained by categorizing these intermediate variables. We propose maximum likelihood inference for this model and we propose algorithms for performing this task. We estimated the parameters of such a model using the data of the 5 year follow-up of the PAQUID study. In particular this analysis yielded interesting results about the effect of educational level on both latent cognitive ability and specific performance in the mini mental test examination. The predictive ability of the model is illustrated by predicting diagnosis of dementia at the 8 year follow-up of the PAQUID study based on the information from the first 5 years.     

Social Security Reform in China's Transition to a Market Economy

This paper begins by describing the origins of a social security system that was based on a series of institutional splits that resulted in the development of a fragmented system characterized by inequity and incomplete coverage. The entitlements embedded in this system have proved difficult to revise in the light of changing circumstances and the pressures associated with economic transition, demographic change and the newly emerging problems of open unemployment and urban poverty. These developments, particularly the latter, are creating new demands on a system already struggling to adjust to structural problems of coverage and financial soundness. A series of extensive reforms in the areas of pensions and unemployment insurance and a rationalization of administrative arrangements and responsibilities have been introduced over the last two decades, but further reform seems inevitable as external pressures and policy priorities change. A key goal of the reform process has been to transfer responsibility for social security from enterprises to the state, but the system still suffers from a series of serious financial problems. Despite the extensive reforms that have already been introduced, these problems and the structural imbalances underlying them will require further action. The most important of these imbalances relate to the split between the nature and role of social security in the urban and rural sectors, the role of the commercial provision and its relationship with the state, and the extension of programmes aimed at poverty alleviation.     

Is Time-Discounting Hyperbolic or Subadditive?

Subadditive time discounting means that discounting over a delay is greater when the delay is divided into subintervals than when it is left undivided. This may produce the most important result usually attributed to hyperbolic discounting: declining impatience, or the inverse relationship between the discount rate and the magnitude of the delay. Three choice experiments were conducted to test for subadditive discounting, and to determine whether it is sufficient to explain declining impatience. All three experiments showed strong evidence of subadditive discounting, but there was no evidence of declining impatience. I conclude by questioning whether hyperbolic discounting is a plausible account of time preference.     

Breaking New Ground: Diverse Routes to College in Rural America*

Abstract Rural communities pose a challenge to status attainment models that explain children's educational attainment primarily in terms of the parents' education and professional status. Alongside the rural professional class are farmers of similar social status but with less education and other families that lack the status and resources of both professional‐class and farm families. The prolonged agricultural crisis in the American Midwest has turned rural youths toward college and has raised questions about the educational value of resources provided by farm parents and other rural parents. We classified youths from the Iowa Youth and Families Project into three SES groups: professional‐managerial, farm, and lower‐status. We compared these groups on resource levels and on the extent to which the resources predicted enrollment in a four‐year college one year after high school. Findings indicated three distinct routes to four‐year college. Professional‐managerial youths tended to follow the traditional path from parents' educational and other resources and support to their own academic involvement and aspirations for higher education. Successful farm youths, in lieu of parental educational advantages, drew on parents' community ties. Resourceful lower‐status youths, in the absence of family background advantages, generated educational attainment through early educational ambition and varied community and school involvements. Even relatively low levels of involvement were valuable to these youths' educational attainment.     

Age at Immigration and Scholastic Achievement in School‐Age Children: Is There A Vulnerable Age?1

This study investigates the relationship between age at immigration and educational achievement at age 14 among all the students (about 45,000) who immigrated to Israel between 1952 and 1970. The relationship is examined for verbal and nonverbal components of an achievement test, in subpopulations defined by gender and ethnic background (Western‐versus Eastern‐born children). The findings indicate a monotonic decrease in achievement as a function of immigration age starting at the age of 7. This decrease is considerably stronger for the Verbal subtest than for the Mathematical subtest, particularly in the Western group. These results refute the vulnerable age hypothesis: They support the view that the foreign language acquisition factor plays a central role in the relationship between age of immigration and scholastic achievement, and are consistent with the expectation of a monotonic decline in achievement as age of immigration increases (and length of residence decreases). Hence, when immigration involves the need to learn a new language, the drop in school achievement is likely to be particularly marked in subject areas requiring higher levels of mastery of the language of instruction. Finally, the results suggest that age 7 may represent a critical age for the scholastic achievement of immigrant students.     

Tertius Dolens: The Student Experience of the University of Manitoba Faculty Association Strike*

Le fondement théorique de notre étude sur l'expérience vécue par les étudiants d'une grève du corps professoral d'une université s'appuie principalement sur la formulation théorique de Blumer selon laquelle l'interaction entre des acteurs, dans un cadre industriel, peut être divisée en trois étapes: 1) interprétation de l'expérience; 2) établissement de nouvelles relations; et 3) direction du mouvement ou ajustement. Chaque étape entraîne un changement de situation ainsi que des modifications correspondantes de la perception de soi et des autres. Dans cette étude, nous intégrons également le travail de Stebbins sur les situations difficiles. Nous appliquons ces concepts fondamentaux à l'étude d'une grève où un élément puissant ‐ la main‐d'ceuvre ‐, représentée ici par le corps professoral, se mesure à un autre élément ‐ la direction ‐, représentée ici par l'administration. Par ailleurs, nous privilégions un point que les autres études perdent souvent de vue: l'effet de cette lutte sur un élément tiers moins puissant, à savoir la population étudiante. The theoretical basis for this study of the student experience of a university faculty strike is provided primarily by Blumer's theoretical formulation that interaction between actors in an industrial setting can be studied in three principal phases: (1) interpretation of the experience; (2) the forging of new and emergent relationships; and (3) lines of movement or adjustment. Each phase involves a change in situation along with corresponding changes in the perception of self and other. We also integrate Stebbins' work on predicaments. These major concepts are employed as we follow a strike in which one powerful sector, labour (represented here as Faculty), is pitted against another, management (represented here as Administration), and focus on what other studies often lose sight of—namely, the effect of the battle on a less powerful third sector, the students.     

In Search of the Lemmus Lemmus: An Investigation into Convergent Competition

This paper explores the reasons for industries converging upon poor strategies. The phenomenon is likened to the periodic mass suicide of the lemmus lemmus (the Norwegian lemming). It gives historic examples of the phenomenon, and evidence of its occurring within a simulated business environment. A literature review shows how it can be explained using theories from economics, psychology and competitive analogies used in business. An inputs-process–outputs model provides a theoretical framework for Lemmus Lemmus strategies and is used to derive hypotheses.     

Japanese marketing strategies in the United Kingdom

This article is based on a study which examined hypotheses about Japanese marketing using a matched sample of British companies and their major Japanese competitors. Japanese subsidiaries in Britain were shown to be much more marketing-oriented, more responsive to strategic opportunities, and more single-minded in their pursuit of market share. Organizationally, there were few differences between the two groups. The Japanese subsidiaries, however, were more inclined to use product or market-based divisions and continuous, informal planning and control procedures. The result is that managerial focus and responsibility are centred upon overall product-market rather than financial or production performance, with continuous feedback facilitating rapid adaptation and implementation of marketing plans and strategy.