A Multivariate Intervention Model for the Dutch Mint Circulation: Estimation and Monte Carlo Simulation

For each of the five Dutch coinage denominations, a transfer-function model is estimated. The output variables are monthly observations of coins in circulation. Two input variables represent transaction flows; all other inputs are step functions, representing the occurrence of interventions. Using the method of cross-correlating the residuals of the individual equations, a multivariate transfer-function model is constructed and estimated. Next Monte Carlo simulation is applied to derive expectations and variances of the yearly addition to the stock of coins until 1996. Our results enlighten on some aspects of a problem situation faced by the Dutch State Mint.     

An algorithm for envy-free allocations in an economy with indivisible objects and money

This paper studies envy-free allocations for economies with indivisible objects, quasi-linear utility functions, and an amount of money. We give a polynomially bounded algorithm for finding envy-free allocations. Connectedness of envy-graphs, which are used in the algorithm, characterizes the extreme points of the polytopes of sidepayments corresponding with envy-free allocations. Received: 22 October 1997/Accepted: 19 January 1999     

The quiet before the storm: anticipating developments in synthetic biology

Synthetic biology aims at designing biological systems, at building ‘living machines’. The emergence of synthetic biology has reignited the cycle of public debate. The old biotechnology debate is being reiterated and the controversies are deepened. The societal debate follows the technological hype cycle. A new technology with a high visibility and high expectations also raises high controversies. For synthetic biology, this hype is currently near its peak and the first signs of disillusionment are getting visible. In policy development, on the other hand, synthetic biology is in the early stages. Governments examine the need for adaptations to existing regulatory frameworks. There is a gap between the visibility of the technological developments and policy formulation. This gap is crucial for technology assessment: while the hype in public attention is over, essential policy steps are taken. In order to close this gap, technology assessment needs to facilitate the societal–ethical debate when media attention, and thus the visibility of the technological developments, declines.     

Ex-post governance in joint ventures: Determinants of monitoring by JV boards of directors

Considerable advances have been made in corporate governance research in recent years and opportunities exist to consider these developments within alliances. We extend the “scope of operations” hypothesis to the domain of joint ventures. This proposition suggests that the monitoring carried out by boards increases when organizations become more complex. The inherent characteristics of JVs generate unique sources of complexity that are currently unexplored in the corporate governance literature. First, we seek to determine their influence on monitoring by using primary data on JV board monitoring. Second, we adopt the size of JV boards as a proxy for monitoring in order to examine whether the determinants of board size and monitoring in fact coincide and to reveal if certain effects are masked by using board size as a simple proxy for monitoring. Doing so enables us to investigate the black-box of what boards actually do as well as extend governance research to other organizational forms. Our findings confirm that the unique characteristics of JVs influence the information needs by the boards resulting in more monitoring by JV directors. Our findings show there is value in bridging alliance theory and the literature on corporate governance research. We also advance practitioner's understanding by providing suggestions on how to structure JV boards in relation to their complexity.     

Migration intentions of rural youth in the Westhoek, Flanders, Belgium and the Veenkoloniën, The Netherlands

‘Should I stay or should I leave my home region?’ is one of the key life course questions that many young people must address as they grow to maturity. Social mobility increasingly presupposes geographical mobility, especially in rural areas. The consequences of the selective out-migration of socially mobile young people (‘brain drain’) are seen as a threat to the economic development and reputation of rural areas. The out-migration of young rural people is often related to participation in higher education and entrance into the labour market. This paper focuses on the migration intentions of pupils in secondary education in two peripheral rural areas: The Westhoek in Flanders, Belgium and the Veenkoloniën in the Netherlands. It analyses, by means of logistic regression analysis, the migration intentions of 611 pupils in the Westhoek and 294 pupils in the Veenkoloniën in relation to their social background, migration history, perceptions of employment opportunities and the way they identify with their home region. In both regions, perceived employment opportunities and local attachment appear to be the most important factors explaining migration intentions. In the Veenkoloniën, in contrast with the Westhoek, migration history, educational level and representations of the region are also important factors determining the migration intentions of young people. These results can be explained by differences in the structure, culture and landscape of the two regions.     

Measuring the effect of changing legislation on the frequency of divorce: The Netherlands, 1830–1990

This article discusses different procedures for measuring the effects of judicial changes on divorce rates. It presents an alternative model and applies it to a historical time series for the Netherlands. In this model, intervention variables were added to a statistical time-series (ARIMA) model. The conclusion of our analysis was that the effects of three judicial changes were only temporary. Revised text of a paper presented at the seminar “The Role of the State and of Public Opinion in Sexual Attitudes and Demographic Behaviour since the 18th Century,” 17th International Congress of Historical Sciences/ Commission Internationale de Démographie Historique, held in Madrid, August 31-September 1, 1990. The views expressed in this paper are those of the authors and do not necessarily reflect the policies of the Netherlands Central Bureau of Statistics.     

Validation of Multimedia Models Assessing Exposure to PAHs—The SOLEX Study

Polluted soils have become a public health problem. While population exposure to soil pollutants is generally quantified using multimedia models, their estimations have not been validated, and studies that attempted to do so are scarce. The objective of the SOLEX study was to compare the predictions of pyrene exposure levels (converted into 1 hydroxypyrene) computed by several models with the results of urinary 1-hydropyrene (1-HOP) assays among 110 employees working at three sites polluted during their past use as manufactured gas plants. Four models were used: AERIS (Canada), CalTOX (California, USA), CLEA (UK), and HESP (The Netherlands). Three occupational exposure scenarios--with office, mixed, and outdoor workers--were constructed, based upon job activities during two measurement campaigns, one in winter and one in summer. The exposure levels estimated by the four models could differ markedly (from 7 up to 80 times) according to the exposure scenario. Also, the predominant exposure routes differed according to the model (direct soil ingestion for HESP and CalTOX, inhalation for AERIS, and dermal absorption for CLEA). The predictions of CalTOX are consistent with the 1-HOP measurements for all the scenarios. For HESP, the consistency is observed for the scenarios, office and mixed, for which the pyrene level in the soil is low. AERIS and CLEA yield results that are systematically above the 1-HOP measurements. This study confirms that validation of the models is crucial and points out to the need to proceed to assess components of the models that are the most influential using appropriate statistical analysis in combination with true field data.