A reply to W. H. James

Abstract The objection of W. H. James to my computation on p. 330, for the sample of Créteil, is valid. For reasons that are developed elsewhere in my paper, the current pregnancy of any woman was omitted in the elaboration of Table 6. Therefore, in order to derive continuation rates, we must re-include this pregnancy in each individual pregnancy history. Since women whose previous pregnancies ended in induced abortions had been excluded, we must do the same for women whose current pregnancy was interrupted by an induced abortion.     

The international transfer of foster parent selection and preparation technology: the example of the Netherlands and the United States

The biannual education conferences of the International Foster Care Organization "provide an opportunity for foster parents and agency staff to learn new ideas and share technical expertise.' Contacts between Dutch and American participants at the 1983 Education Conference led to the transfer and adaptation of an American foster parent selection-preparation program to the Netherlands. This article, based on a workshop presented at the 1989 Education Conference, describes the process and initial impact of this international experience.     

Critical capabilities for widening international new ventures’ geographical scope.

Current findings are still inconclusive with regard to the role played by the characteristics of social networks in INVs’ early geographical scope. This study analyses how entrepreneurial-oriented networks affect new ventures’ early geographical scope through critical capabilities. We have adopted a behavioural perspective to investigate the effect of social networks both on international new ventures’ geographical scope and on their critical capabilities such as absorptive and adaptive capabilities. Results from a sample of 183 Spanish international ventures confirm the importance of entrepreneurial orientation as a network characteristic for early geographical scope. Additionally, the positive effect of adaptive capability on new ventures’ early geographical dispersion has been confirmed but not so in the case of absorptive capabilities. Our results suggest that future research must be careful to assume international new ventures’ absorptive capability as a prerequisite to their cross-border expansion.     

Approximation algorithms and hardness results for labeled connectivity problems

Let G=(V,E) be a connected multigraph, whose edges are associated with labels specified by an integer-valued function ℒ:E→ℕ. In addition, each label ℓ∈ℕ has a non-negative cost c(ℓ). The minimum label spanning tree problem (MinLST) asks to find a spanning tree in G that minimizes the overall cost of the labels used by its edges. Equivalently, we aim at finding a minimum cost subset of labels I⊆ℕ such that the edge set {e∈E:ℒ(e)∈I} forms a connected subgraph spanning all vertices. Similarly, in the minimum label s – t path problem (MinLP) the goal is to identify an s–t path minimizing the combined cost of its labels. The main contributions of this paper are improved approximation algorithms and hardness results for MinLST and MinLP.     

Tempo and the TFR

Tempo effects in period fertility indicators are widely regarded as a source of bias or distortion. But is this always the case? Whether tempo change results in bias depends, in the view advanced here, on the measure used, the meaning of bias/distortion, and the objective of analysis. Two ways of construing bias in period measures are suggested, and their relevance is discussed in the context of five broad purposes for measuring period fertility: describing and explaining fertility time trends, anticipating future prospects, providing input parameters for formal models, and communicating with nonspecialist audiences. Genuine timing effects are not biasing when period fertility is the explanandum but are distorting when the aim is to estimate cohort fertility. Alternatives to tempo adjustment are available that are a more defensible solution to the issue of timing change. Tempo adjustment could be more fruitfully considered a form of modeling rather than empirical measurement. The measurement of period fertility could be improved by relying more on a statistical approach and less on indicators based on stable assumptions. Future progress will depend on integrating research on measurement with substantive investigation.     

Institutional Dynamics in European Industrial Relations

Since the end of the 1970s, all European systems of industrial relations have experienced some common developments. In order to shed some light on this subject we look for common as well as specific changes within some selected systems of industrial relations in Europe. Therefore, we deal with the moving forces behind these tendencies which are, on the whole, global in character. We discuss the institutional responses to these general developments in the United Kingdom, France, and Germany. These countries have been chosen because their industrial relations are generally seen as belonging to different types of systems. We conclude that many responses are still national specific and, in line with the distinguished national logics of collective action, to be defined respectively as the logic of contract, the logic of opposition and the logic of cooperation. At the end some reflections about the future of European industrial relations are presented.     

Reliability of reasons for early termination of breastfeeding: application of a bivariate probability model with sample selection to data from surveys in Malaysia in 1976-77 and 1988-89

Although extensively collected, data on people's reasons for their behaviour provided retrospectively have been met with some scepticism on the grounds that they may be subject to biases and errors that jeopardize their usefulness. This study investigates, for a sample of 1,327 births, the reliability with which women in Peninsular Malaysia recalled, at intervals 12 years apart, reasons for not initiating or for stopping breastfeeding less than 3 months after a birth. Overall, we find low to moderate reliability of recall. Levels of reliability are relatively high for some reasons (the child died and no or insufficient milk) but low for some others (child ill, breastfeeding inconvenient). Results from selection models show that reliability does not vary with the length of time since the child's birth but is inversely related to socio-economic status (proxied by education and employment). Social status, social norms, and health-related factors appear to be significant influences on women's consistency of reporting.     

Asymmetric social protection systems with migration

We study the consequences of the coexistence of different social protection systems on contribution rate levels and migration in a two-country model. Before any migration takes place, the levels of contribution rates are chosen by a representative elected in each country. The migration of each agent depends on her anticipation of other agents’ migrations. We show that the richest agents are attracted to the Bismarckian country. The poorest agents tend to migrate toward one country or the other depending on the Beveridgean country contribution rate. The Beveridgean country can set a higher contribution rate to limit the departures of rich agents.

On the use of extreme value tail modeling for generalized pairwise comparisons with censored outcomes

In randomized clinical trials, methods of pairwise comparisons such as the ‘Net Benefit’ or the ‘win ratio’ have recently gained much attention when interests lies in assessing the effect of a treatment as compared to a standard of care. Among other advantages, these methods are usually praised for delivering a treatment measure that can easily handle multiple outcomes of different nature, while keeping a meaningful interpretation for patients and clinicians. For time-to-event outcomes, a recent suggestion emerged in the literature for estimating these treatment measures by providing a natural handling of censored outcomes. However, this estimation procedure may lead to biased estimates when tails of survival functions cannot be reliably estimated using Kaplan–Meier estimators. The problem then extrapolates to the other outcomes incorporated in the pairwise comparison construction. In this work, we suggest to extend the procedure by the consideration of a hybrid survival function estimator that relies on an extreme value tail model through the Generalized Pareto distribution. We provide an estimator of treatment effect measures that notably improves on bias and remains easily apprehended for practical implementation. This is illustrated in an extensive simulation study as well as in an actual trial of a new cancer immunotherapy.