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This study investigated developmental differences in the relationship of probability and cost estimates to worrying. Adults, younger children ( M age = 8.67 years) and older children ( M age = 11.06 years) rated the extent to which they worry about a list of negative social and physical outcomes and provided subjective probability and cost estimates for the same outcomes. Adults reported worrying more about social outcomes and rated them as less ‘bad’ (or costly) but more likely to occur than physical outcomes. Unlike adults, children in both age groups reported worrying more about physical outcomes. However, similar to adults, they also rated social outcomes as less ‘bad’ but more likely to occur than physical outcomes. Regression analyses showed that probability ratings were the best predictors of worry in adults, both probability and cost ratings equally predicted worry in older children, but only cost ratings predicted worry in younger children. [ABSTRACT FROM AUTHOR]

Contingent valuation has become one of the dominant methods for valuing nonmarketed environmental goods, as well as for damage assessment due to natural hazards. In this study, the method is applied for evaluating the household willingness to pay for a flood control project in an impoverished periphery of Rio de Janeiro, Brazil. Theoretical validity is analyzed via a binary logistic regression, which describes the impact of sociodemographic, dwelling characteristics, and flood related variables on the willingness to pay for the project. Analysis of content validity indicates a series of characteristics—uncertainty, novelty, lack of well-differentiated values, institutional setting, and entitlement structure—which appear to drastically limit the use of contingent valuation for flood control projects in low income areas of developing countries. The study concludes that the method, in it’s current formulation, is not appropriate for use in policy decisions about flood control investments in areas described by a concentration of low income households in developing countries. [ABSTRACT FROM AUTHOR]

Abstract: Modern maintenance strategies for deteriorating structures are typically based on minimizing total cost. Extensions of this concept into the nondeterministic range allow to take into account the uncertainty in total cost. In this paper, the probability of exceeding a total cost threshold is included in the structure maintenance optimization problem. In addition, the probabilities of violating acceptable levels of safety and condition are computed. Based on this, an optimization task can be formulated and solved in which these probabilities can be included into the formulation of the objective function and the constraint conditions. Smoothing of the Monte-Carlo-based results is carried out utilizing a smoothing procedure by regression methods which are well-known for the response surface approach. Both time-based maintenance and performance-based maintenance are taken into account. The total maintenance cost is minimized with respect to parameters of both types of maintenance. Taking into account the cost of failure, optimal values for the threshold safety level and the time interval between subsequent maintenance applications are obtained. It is shown that different design parameters can lead to the same total cost thus allowing for a trade-off between time-based maintenance and performance-based maintenance at the discretion of the structure maintenance manager. [Copyright &y& Elsevier]