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Researchers have puzzled over the finding that countries that ratify UN human rights treaties such as the Convention Against Torture are more likely to abuse human rights than non-ratifiers over time. This article presents evidence that the changing standard of accountability – the set of expectations that monitoring agencies use to hold states responsible for repressive actions – conceals real improvements to the level of respect for human rights in data derived from monitoring reports. Using a novel dataset that accounts for systematic changes to human rights reports, it is demonstrated that the ratification of human rights treaties is associated with higher levels of respect for human rights. This positive relationship is robust to a variety of measurement strategies and model specifications.

Why do only some powerful states choose to develop power projection capabilities? To answer this question, we test the proposition that states choose to develop power projection capabilities when they face a competitive geopolitical environment. This proposition is derived from our theory, which is used to construct a new measure of the level of geopolitical competition that every state in the system faces. This measure incorporates each state's relative geographic position to every other state in the international system, the relative amount of economic power of those other states, and the degree to which their interests are compatible. We then apply this unique country-year measure to test the proposition that competitive environments are associated with the development of power projection capabilities, as measured by the tonnage of naval ships maintained by each country in each year. We demonstrate that our measure helps explain the degree to which states choose to invest in power projection capabilities. This provides an explanation for why the world has been economically multipolar, but military unipolar, for the past quarter century, and why this might change in the future, as rising powers with incompatible interests are increasing their investment in power projection capabilities.

We argue that political sciexntists can provide additional evidence for the predictive validity of observational and quasi-experimental research designs by minimizing the expected prediction error or generalization error of their empirical models. For observational and quasi-experimental data not generated by a stochastic mechanism under the researcher's control, the reproduction of statistical analyses is possible but replication of the data-generating procedures is not. Estimating the generalization error of a model for this type of data and then adjusting the model to minimize this estimate—regularization—provides evidence for the predictive validity of the study by decreasing the risk of overfitting. Estimating generalization error also allows for model comparisons that highlight underfitting: when a model generalizes poorly due to missing systematic features of the data-generating process. Thus, minimizing generalization error provides a principled method for modeling relationships between variables that are measured but whose relationships with the outcome(s) are left unspecified by a deductively valid theory. Overall, the minimization of generalization error is important because it quantifies the expected reliability of predictions in a way that is similar to external validity, consequently increasing the validity of the study's conclusions.