ALL-BIAS DESIGNS FOR POLYNOMIAL SPLINE REGRESSION MODELS

Polynomial spline regression models of low degree have proved useful in modeling responses from designed experiments in science and engineering when simple polynomial models are inadequate. Where there is uncertainty in the number and location of the knots, or breakpoints, of the spline, then designs that minimize the systematic errors resulting from model misspecification may be appropriate. This paper gives a method for constructing such all‐bias designs for a single variable spline when the distinct knots in the assumed and true models come from some specified set. A class of designs is defined in terms of the inter‐knot intervals and sufficient conditions are obtained for a design within this class to be all‐bias under linear, quadratic and cubic spline models. An example of the construction of all‐bias designs is given.     

Demographic Shifts in the Czech Republic after 1989: A Second Demographic Transition View

A dramatic change in fertility,family formation and living arrangements tookplace in the Czech Republic over the 1990s. Theestablishment of democracy, profound socialtransformation and transition to the marketeconomy affected the values and demographicbehaviour of the young Czech generation. Thispaper examines whether these demographic shiftscan be interpreted within the framework of thesecond demographic transition. The theoreticalpart discusses the idea of the transition,outlining three distinctive conceptualisations.Two of them – the view of the transition as aprogression of characteristic interrelateddemographic changes and a broader viewstressing the importance of underlyingideational factors – fit the Czech situationvery well. A comparison with the Netherlandsreveals that the onset of the transition in theCzech Republic may be clearly located in thefirst half of the 1990s, lagging two decadesbehind the Netherlands.     

Using Probabilistic Terrorism Risk Modeling for Regulatory Benefit-Cost Analysis: Application to the Western Hemisphere Travel Initiative in the Land Environment

This article presents a framework for using probabilistic terrorism risk modeling in regulatory analysis. We demonstrate the framework with an example application involving a regulation under consideration, the Western Hemisphere Travel Initiative for the Land Environment, (WHTI‐L). First, we estimate annualized loss from terrorist attacks with the Risk Management Solutions (RMS) Probabilistic Terrorism Model. We then estimate the critical risk reduction, which is the risk‐reducing effectiveness of WHTI‐L needed for its benefit, in terms of reduced terrorism loss in the United States, to exceed its cost. Our analysis indicates that the critical risk reduction depends strongly not only on uncertainties in the terrorism risk level, but also on uncertainty in the cost of regulation and how casualties are monetized. For a terrorism risk level based on the RMS standard risk estimate, the baseline regulatory cost estimate for WHTI‐L, and a range of casualty cost estimates based on the willingness‐to‐pay approach, our estimate for the expected annualized loss from terrorism ranges from $2.7 billion to $5.2 billion. For this range in annualized loss, the critical risk reduction for WHTI‐L ranges from 7% to 13%. Basing results on a lower risk level that results in halving the annualized terrorism loss would double the critical risk reduction (14–26%), and basing the results on a higher risk level that results in a doubling of the annualized terrorism loss would cut the critical risk reduction in half (3.5–6.6%). Ideally, decisions about terrorism security regulations and policies would be informed by true benefit‐cost analyses in which the estimated benefits are compared to costs. Such analyses for terrorism security efforts face substantial impediments stemming from the great uncertainty in the terrorist threat and the very low recurrence interval for large attacks. Several approaches can be used to estimate how a terrorism security program or regulation reduces the distribution of risks it is intended to manage. But, continued research to develop additional tools and data is necessary to support application of these approaches. These include refinement of models and simulations, engagement of subject matter experts, implementation of program evaluation, and estimating the costs of casualties from terrorism events.     

Leveraging middle managers’ brokerage for corporate entrepreneurship: The role of multilevel social capital configurations

Building on recent efforts to bring a socio-political perspective to social capital research, we develop and test a multilevel framework that explains why middle managers who occupy brokerage positions differ in their ability and willingness to engage in entrepreneurial behavior. More specifically, we provide a contextualized understanding of the links among middle managers' brokerage, their political-support ties, and their personal initiative. Results derived from data on 383 middle managers and 72 top managers in 34 business units indicate that political-support ties with top managers strengthen the relationship between middle managers’ brokerage and personal initiative. However, this positive effect depends on the social capital resources available in the focal business unit. It is attenuated in business units with a supportive and trusting social context and amplified in business units with high levels of internal connectedness. By uncovering these incompatibilities and complementarities, our study demonstrates the value of accounting for different social capital configurations and the interplay of their inherent social capital resources when examining the effects of brokerage on corporate entrepreneurship.     

Socioeconomic,sociodemographic and attitudinal correlates of the tempo of divorce

The association between sociodemographic, demographic, and attitudinal measures and the timing or tempo of marital dissolution over a 14-year time span is examined. Separation is considered equivalent to divorce. Early and late divorce are differentiated by whether the event occurred before or after the average number of years married prior to divorce. Data were obtained on husbands and wives within childbearing years (up to 39 years) in the 1st years of the 1st marriage. A random stratified sample of 610 couples was drawn from records of marriages in a midwestern county between 1972-77. Reinterviews were conducted on 544 couples in April 1985. socioeconomic variables included educational attainment, occupational prestige, wife's employment status, wife's future work plans, husband's attitude to wife's future work plans, total family income, and level of satisfaction with current financial status. Demographic variables are age at marriage, number of children in 1985, marital duration, and desired family size. Attitudinal items were religiosity and gender role orientations (traditionalism, modernism, egalitarianism). Exposure to divorce was not equitably distributed for the 108 who divorced, but this was not statistically significant. The results indicate that those divorced earlier were wives who worked outside the home, worked at more prestigious jobs, planned to be employed throughout married life, and whose father had a higher level of educational attainment. This finding is not consistent with prior research which has shown that favorable socioeconomic conditions lower the probability of divorce. The timing of divorce was affected by the presence of children. Those married at younger ages divorced earlier and couples with children delayed divorcing longer than couples without children. These findings were consistent with earlier research. Catholic wives delayed divorce longer than non-Catholic wives. Males lower in sexual satisfaction divorced earlier. Divorce was postponed longer for husbands with traditional values and wives who had higher scores on egalitarianism. Wives with scores on modernism had earlier divorces than wives scoring lower on modernism. The tempo of divorce was in multiple classification analysis predicted best by wife's employment status and number of children. Cross-classification was not possible.