Bayes Hilbert Spaces

A Bayes linear space is a linear space of equivalence classes of proportional σ‐finite measures, including probability measures. Measures are identified with their density functions. Addition is given by Bayes' rule and substraction by Radon–Nikodym derivatives. The present contribution shows the subspace of square‐log‐integrable densities to be a Hilbert space, which can include probability and infinite measures, measures on the whole real line or discrete measures. It extends the ideas from the Hilbert space of densities on a finite support towards Hilbert spaces on general measure spaces. It is also a generalisation of the Euclidean structure of the simplex, the sample space of random compositions. In this framework, basic notions of mathematical statistics get a simple algebraic interpretation. A key tool is the centred‐log‐ratio transformation, a generalization of that used in compositional data analysis, which maps the Hilbert space of measures into a subspace of square‐integrable functions. As a consequence of this structure, distances between densities, orthonormal bases, and Fourier series representing measures become available. As an application, Fourier series of normal distributions and distances between them are derived, and an example related to grain size distributions is presented. The geometry of the sample space of random compositions, known as Aitchison geometry of the simplex, is obtained as a particular case of the Hilbert space when the measures have discrete and finite support.     

Dynamic Pricing with Constant Demand Elasticity

The celebrated model of Gallego and van Ryzin is specialized to the case of constant elasticity of demand. A closed form is developed, which has an even simpler form than that arising with exponential demand and which possesses an excellent approximation. In this environment, monopoly is efficient, which means that all the behavior usually attributed to monopoly pricing is actually a consequence of efficient pricing and would arise even in a perfectly competitive environment. If the initial supply is not too large, consumers have no incentive to delay their purchases to get a lower price at the average inventory prevailing at any time.     

A Psychometric Analysis of Field Evaluation Instruments Designed to Measure Students’ Generalist-Level Social Work Competencies

ABSTRACT

There is a dearth of research on the evaluation of the psychometric performance of instruments designed to measure students’ generalist-level social work competencies. There is also uncertainty on the performance of various response option formats used to measure students’ competencies in assessment instruments. Using a sample of 198 master of social work students and 198 field instructors, the current study employs confirmatory factor analysis to assess the psychometric performance of a field evaluation instrument designed to measure students’ generalist-level social work competencies. The results provide evidence to support the validity and reliability of the instrument. The results also highlight nuances associated with a 5-point response option format for items used to measure competency indicators. Implications, limitations, and directions for future research are discussed.     

Adult Attachment and Stepparenting Issues: Couple Relationship Quality as a Mediating Factor

Using a sample of 390 stepparents, we assess the influence of insecure attachment and couple relationship quality on stepparenting issues. We also examine the extent to which relationship quality mediates connections between attachment and stepparenting issues. Results from ordinary least squares regression and Sobel tests indicate greater levels of attachment avoidance and anxiety are associated with greater levels of stepparenting issues. Results also indicate greater levels of relationship satisfaction and stability are associated with less stepparenting issues. Relationship satisfaction and stability significantly mediate the influence of attachment anxiety on stepparenting issues. Limitations, implications, and directions for future research are discussed.     

International conference on Jewish civilization in eastern and central Europe,Minsk, 24–26 January 2000

A Symposium on Soviet Jewry

The Jews in Soviet Russia, Since 1917, Lionel Kochan (ed.). London, Oxford University Press for Institute of Jewish Affairs. 1970. ix + 357 pp. Index. £2.50.

Wanted: a history of Soviet Jewry

The Silent Millions: A History of the Jews in the Soviet Union by Joel Cang. London, Rapp and Whiting. 1969. 246 pp. £2.10.

Red Rose

Rosa Luxemburg, Ich War — Ich Bin — Ich Werede Sein, by Harry Wilde. Wien‐Muenchen‐Zurich, Verlag Fritz Molden. 1970. 264 pp.

A Book on Georgian Jewry

Yehudey Gruzia: Ma'avak Al Ha'shiva Le‐tsion (The Jews of Eorgia: A Struggle for the Return to Zion), by Mordecai Neishtat. Tel‐Aviv, Am Oved Publishers, Ltd. 1970. 148 pp. (in Hebrew).

Menshevism and the Jewish question

Russian Social Democracy; the Menshevik Movement. A Bibliography, by Anna M. Bourgina. Hoover Institution Bibliographical Series: XXXVI, The Hoover Institution on War, Revolution and Peace, Stanford University, Stanford, California. 1968. 392 pp. (no price listed), (in Russian; English introduction).

Jewish writers of Byelorussia

Pismienniki Savieckaj Bielarusi: Karotki Bijabiblijahraficny Davednik (Writers of Soviet Byelorussia: a short Biobibliography), A. Harodzicki et al (comp.). Minsk, Vydavectva ‘Bielarus’. 1970. 440 pp. 82 kopeks.     

Perceived Stepparent–Child Relationship Quality: A Systematic Review of Stepchildren's Perspectives

Stepfamily scholars have emphasized the importance of including stepchildren in the analysis and discussion of stepfamily life. This systematic review synthesized recent research examining predictors/correlates of stepparent–child relationship quality from the viewpoint of stepchildren in the United States. Five bibliographic databases were searched, resulting in 631 potentially relevant studies for review. Manual searches of three prominent family studies journals were also conducted. Screening and eligibility assessment based on a priori inclusion criteria yielded a final sample of 23 studies, including published studies and reports found in the “gray” literature. Significant predictors/correlates associated with stepchildren's perceptions of stepparent–child relationship quality were grouped into the following conceptual domains: individual characteristics, family characteristics, features of (step)parent–child interactions, and stepcouple dynamics. Limitations, implications, and future research directions are discussed.     

Family allowances in France

We model the impact of past migration on fertility, assessing the separate effects of relative urbanization of the destination, as a proxy for norms, and post-migration employment, as a proxy for opportunity costs. In the Philippines, we find that large fertility declines accompany post-migration employment. If not followed by work for pay, the estimated fertility impact of migration is small. We find little evidence of migrant selectivity in fertility, and offer speculative evidence that fertility disruption accompanying migration may be large enough to account for much of the apparent effect of normative adaptation.     

Playing,Sitting Out,and Observing the Game: An Investigation of Faculty Members’ Perspectives on Political Behavior in Ethical Decision Making

Ethical dilemmas are inherently ambiguous, complex, and ill-defined. Additionally, these dilemmas involve multiple stakeholders. These characteristics may induce political behavior as a resolution tactic. Thus, the goal of the present effort was to investigate perspectives on politics among researchers in an ethical decision-making context. A qualitative analysis of interviews with university faculty members revealed that faculty members’ perspectives on political behavior in an ethical decision-making context fall into a number of categories, including positive, negative, and realistic views of political activity. The implications of these varying perspectives on ethical decision making are discussed.