MMCTest—A Safe Algorithm for Implementing Multiple Monte Carlo Tests

Consider testing multiple hypotheses using tests that can only be evaluated by simulation, such as permutation tests or bootstrap tests. This article introduces MMCTest , a sequential algorithm that gives, with arbitrarily high probability, the same classification as a specific multiple testing procedure applied to ideal p‐values. The method can be used with a class of multiple testing procedures that include the Benjamini and Hochberg false discovery rate procedure and the Bonferroni correction controlling the familywise error rate. One of the key features of the algorithm is that it stops sampling for all the hypotheses that can already be decided as being rejected or non‐rejected. MMCTest can be interrupted at any stage and then returns three sets of hypotheses: the rejected, the non‐rejected and the undecided hypotheses. A simulation study motivated by actual biological data shows that MMCTest is usable in practice and that, despite the additional guarantee, it can be computationally more efficient than other methods.     

Developing a Social Protection Index for Asia

Social protection is increasingly seen as an important tool for poverty reduction, but to date there have been few quantitative cross‐country assessments of social protection provision. This article develops a social protection index that systematically and consistently quantifies activities at the national level. Four summary indicators representing the cost, coverage, poverty targeting and impact are scaled and weighted to produce an additive index of the overall level of social protection provision. The index is calculated for six very different Asian countries: Bangladesh, Indonesia, Mongolia, Nepal, Pakistan and Vietnam. Considerable contrasts are revealed between their levels of social protection provision.     

The Uses and Abuses of Co-Therapy

The literature on co-therapy suggests increased interest in this treatment procedure. There is some agreement over advantages and disadvantages, but there is also confusion on indications and counter-indications. This paper summarizes the current use and abuse of co-therapy. The reported clinical experiences of several co-therapist teams, including spouse co-therapists, are also discussed. It appears that co-therapy will remain controversial until outcomes are rigorously measured and compared with the results of other therapeutic modalities in a standardized, acceptable way.     

An Evolutionary Analysis of Buyer Insurance and Seller Reputation in Online Markets

Applying an evolutionary framework, we investigate how a reputation mechanism and a buyer insurance (as used on Internet market platforms such as eBay) interact to promote trustworthiness and trust in markets with moral hazard problems. Our analysis suggests that the costs involved in giving reliable feedback determine the gains from trade that can be obtained in equilibrium. Buyer insurance, on the other hand, can affect the trading dynamics and equilibrium selection. We find that, under reasonable conditions, buyer insurance crowds out trust, and trustworthiness. Ockenfels gratefully acknowledges the support of the Deutsche Forschungsgemeinschaft. Mengel’s research was supported by the Spanish Ministry of Education and Science (grant SEJ 2004-02172).     

Scoring predictions at extreme quantiles

AStA Advances in Statistical Analysis - Prediction of quantiles at extreme tails is of interest in numerous applications. Extreme value modelling provides various competing predictors for this...