Some new factor screening designs using the search linear model

Factor screening designs for searching two and three effective factors using the search linear model are discussed. The construction of such factor screening designs involved finding a fraction with small number of treatments of a 2^m factorial experiment having the property P_2t (no 2t columns are linearly dependent) for t=2 and 3. A ‘Packing Problem’ is introduced in this connection. A complete solution of the problem in one case and partial solutions for the other cases are presented. Many practically useful new designs are listed.     

Perspectives on Corporate Control: Implications for CEO Compensation

This study examines the influence on CEO paypractices of four corporate control perspectives:managerial control, class hegemony, external control,and efficient market. The results indicate the influence of both market and extra-market controls on thedetermination of CEO pay levels and criteria.Implications for the governance of firms and the studyof corporate control are drawn.     

Do Drivers of Small Cars Take Less Risk in Everyday Driving?

Previously reported observed data on risky everyday driving are brought together and reanalyzed in order to focus on the relation between risky driving and the size of the car being driven, as indicated by car mass. The measures of risky driving include separation between vehicles in heavy freeway traffic and speed on a two lane road. Observed seat belt use provides a third measure of driver risk. Confounding effects arising from the observed association between car mass and driver age are taken into account by segmenting the data into three driver age groups. Driver risk taking is found to increase with increasing car mass for each of these three aspects of everyday driving. The implications of these results with respect to driver fatality rates are discussed in terms of a simple model relating observed risky driving to the likelihood of involvement in a severe crash.     

Rail safety and rail privatization

Privatisation of the state-owned British railway system was completed in 1997. The following 6 years saw four serious fatal train accidents, leading to 49 deaths. These were the train collisions at Southall in 1997 and Ladbroke Grove in 1999, each caused by trains passing red signals, and the derailments at Hatfield in 2000 and Potters Bar in 2002, each caused by defective track. Has safety been compromised by the sell-off of the railways? Andrew Evans looks at the evidence and asks has privatisation led to more accidents?