Cost functions as the foundation of managerial decision making usually assume a linear cost function with fixed and variable costs. The latter are dominantly regarded as being identical for increasing and for decreasing activity levels. However, empirical research shows that the decline in costs...

Bootstrap aggregating or Bagging, introduced by Breiman (1996a), has been proved to be effective to improve on unstable forecast. Theoretical and empirical works using classification, regression trees, variable selection in linear and non-linear regression have shown that bagging can generate...