These first ten authors contributed equally to this work.

We conduct a genome-wide association study (GWAS) of educational attainment (EA) in a sample of ~3 million individuals and identify 3,952 approximately uncorrelated genome-wide-significant single-nucleotide polymorphisms (SNPs). A genome-wide polygenic predictor, or polygenic index (PGI), explains 12–16% of EA variance and contributes to risk prediction for ten diseases. Direct effects (i.e., controlling for parental PGIs) explain roughly half the PGI’s magnitude of association with EA and other phenotypes. The correlation between mate-pair PGIs is far too large to be consistent with phenotypic assortment alone, implying additional assortment on PGI-associated factors. In an additional GWAS of dominance deviations from the additive model, we identify no genome-wide-significant SNPs, and a separate X-chromosome additive GWAS identifies 57.

It has become increasingly popular to carry out cost-effectiveness analyses in economic evaluations of healthcare programmes. Cost-effectiveness analysis is based on the maximisation of the health effects for a given amount of resources. However, many published studies fail to report the results of cost-effectiveness analysis in a way that is consistent with this underlying aim. The aim of this article is to demonstrate the decision rules of cost-effectiveness analysis in an easily accessible way for practitioners in the field. A hypothetical example is used to demonstrate the decision rules of cost-effectiveness analysis, and we also show how to estimate the appropriate incremental cost-effectiveness ratios and how to exclude dominated alternatives. It is then shown how fixed budgets or predetermined prices per effectiveness unit can be used as decision rules to maximise health effects and to determine which programmes to implement on the basis of incremental cost-effectiveness ratios. We hope that the article will contribute towards an increased understanding and application of the appropriate decision rules of cost-effectiveness analysis, so that the results of cost-effectiveness analyses can be interpreted meaningfully by decision makers.

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In this paper the results of an experiment comparing the dichotomous choice (DC) contingentvaluation (CV) approach with real purchase decisions for a consumer good are reported. In addition to comparing the standard DC CV approach with real decisions, we also test the hypothesis that a more conservative interpretation of the DC approach, where only absolutely sure yes responses are counted as yes responses, correctly predicts real purchase decisions. The results show that the hypothetical yes responses overestimate the real yes responses and that the hypothetical absolutely sure yes responses underestimate the real yes responses.