A relaxation procedure for calculating (G–)minimax optimal designs

Summary: In nonlinear statistical models, standard optimality functions for experimental designs depend on the unknown parameters of the model. An appealing and robust concept for choosing a design is the minimax criterion. However, so far, minimax optimal designs have been calculated efficiently under various restrictive conditions only. We extend an iterative relaxation scheme originally proposed by Shimizu and Aiyoshi (1980) and prove its convergence under very general assumptions which cover a variety of situations considered in experimental design. Application to different specific design criteria is discussed and issues of practical implementation are addressed. First numerical results suggest that the method may be very efficient with respect to the number of iterations required.*Supported by a grant from the Deutsche Forschungsgemeinschaft. We are grateful to a referee for his constructive suggestions.     

Legitimation, Geographical Scale, and Organizational Density: Regional Patterns of Foundings of American Automobile Producers, 1885–1981

Do organizational processes of legitimation and competition operate within different boundaries corresponding to different geographical levels of analysis? Following Hannan et al. (1995), this analysis explores the possibility that legitimation operates on a broader geographical scale (less constrained by political and physical barriers) than does competition. We test the argument by examining founding rates of American automobile producers from 1885 to 1981, within the framework of density-dependent modeling. Our findings suggest that within the United States, legitimation operated on a national scale while competition proceeded primarily on a regional level. Comparison with automobile producer populations in Europe yields differences in application and interpretation of the theory.     

Social Work with Rural Peoples (3rd ed.), Ken Collier,Vancouver, BC: New Star Books, 2006, Paper

This qualitative study explored how White parents who identify as antiracist apply antiracism principles to parenting their White children. Participants discussed how they attempt to incorporate antiracism values into their parenting, their children’s racial awareness, and the impact of race and racism on their children. Our findings indicate significant inconsistencies between antiracist values and parenting practices. The main difference between antiracist White parents and nonantiracist-identified White parents was awareness. Although antiracist White parents overall conveyed an awareness of racism as a system of unearned privileges, there was minimal modeling of antiracist action.     

Collaborative concept development using supplier competitions: Insights from the automotive industry

Firms may seek to collaborate with skilled suppliers not only to access existing technologies but also to jointly develop new concepts. We sought to examine the details of collaborative concept development through matched cases of novel convertible roof projects in the European automotive industry. The result is a three phase model marked by the use of supplier concept competitions to probe possible features and by the selective maintenance of distance to suppliers. Knowledge transfer and integration practices, differences depending on initial experience, and implications for managing such distributed systems of innovation are highlighted.