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In this article we study post-model selection estimators that apply ordinary least squares (OLS) to the model selected by first-step penalized estimators, typically Lasso. It is well known that Lasso can estimate the nonparametric regression function at nearly the oracle rate, and is thus hard to improve upon. We show that the OLS post-Lasso estimator performs at least as well as Lasso in terms of the rate of convergence, and has the advantage of a smaller bias. Remarkably, this performance occurs even if the Lasso-based model selection \"fails\" in the sense of missing some components of the \"true\" regression model. By the \"true\" model, we mean the best s-dimensional approximation to the nonparametric regression function chosen by the oracle. Furthermore, OLS post-Lasso estimator can perform strictly better than Lasso, in the sense of a strictly faster rate of convergence, if the Lasso-based model selection correctly includes all components of the \"true\" model as a subset and also achieves sufficient sparsity. In the extreme case, when Lasso perfectly selects the \"true\" model, the OLS post-Lasso estimator becomes the oracle estimator. An important ingredient in our analysis is a new sparsity bound on the dimension of the model selected by Lasso, which guarantees that this dimension is at most of the same order as the dimension of the \"true\" model. Our rate results are nonasymptotic and hold in both parametric and nonparametric models. Moreover, our analysis is not limited to the Lasso estimator acting as a selector in the first step, but also applies to any other estimator, for example, various forms of thresholded Lasso, with good rates and good sparsity properties. Our analysis covers both traditional thresholding and a new practical, data-driven thresholding scheme that induces additional sparsity subject to maintaining a certain goodness of fit. The latter scheme has theoretical guarantees similar to those of Lasso or OLS post-Lasso, but it dominates those procedures as well as traditional thresholding in a wide variety of experiments.

The future of liberal internationalism will be influenced increasingly by the re-emergence of China as a major power on the world stage and by the way the United States is reacting to China’s growing influence. In this article, we discern three possible scenarios: one of inevitable conflict, one of gradual co-optation and a hybrid scenario of coexistence. We argue that in order to understand the development of the Sino-US relationship and the sometimes-contradictory outcomes and dilemmas this generates, we need to take into account the social and domestic sources of foreign policy within these two major powers, and the distinctive state–society models that they represent. Crucially, this includes how the domestic political economy is dynamically interrelated with the global political economic context. In our approach, foreign policy elites form a key nexus here and a vital prism through which to analyse foreign policy strategies. From this critical political economy perspective, we will describe how China’s re-emergence as a world power is partly shaped by its distinctive ‘statist’ state–society model, to then analyse US strategy towards rising China through the lens of the close nexus between America’s corporate elite and the state. In our concluding section we will return to the three scenarios. Based on the findings presented, and in light of the radical shift that seems to be occurring due to the Trump presidency, we will reflect on the likelihood of these scenarios, the future of the liberal world order and conclude with a research agenda.

Credible causal inference in accounting and finance research often comes from natural experiments. These experiments can be exploited using several shock-based research designs, including difference in differences (DID), shock-based instrumental variable (shock-IV), and regression discontinuity. We study here shock-IV designs using panel data. We identify all shock-IV papers in two broad data sets and reexamine three of the apparently strongest papers—Desai and Dharmapala [Desai M, Dharmapala D (2009) Corporate tax avoidance and firm value. Rev. Econom. Statist. 91:537–546.], Duchin et al. [Duchin R, Matsusaka J, Ozbas O (2010) When are outside directors effective? J. Financial Econom. 95:195–214.], and Iliev [Iliev P (2010) The effect of SOX Section 404: Costs, earnings quality, and stock prices. J. Finance 65:1163–1196.]. After we enforce covariate balance and common support for treated and control firms, the instruments in all three papers are unusable—they are no longer significant in the first stage. All three papers also show nonparallel pretreatment trends on outcomes or core covariates. The problems with these papers generalize to our full sample and to other papers exploiting the same shocks as Duchin et al. A core conclusion of our reexamination is that pretreatment balance (common support, covariate balance, and parallel pretreatment trends) is necessary for credible shock-IV designs. We provide a good-practice checklist for shock-IV design with panel data, much of which also applies to DID designs. This paper was accepted by Shiva Rajgopal, accounting.

State-centered Christian statism (CS) and society-centered religious traditionalism (RT) are two conservative religious nationalist ideologies that share Christian symbolisms but contain different attitudes about how the state and religion should interact; specifically, CS reflects the belief that Christianity needs to be the guiding ideology of the federal government, and RT mainly promotes the Christian ethos within civil society. We investigate whether these two ideologies predict different forms of religiosity. Analyzing the Baylor Religion Survey (Wave 6), we find that religious believers with stronger agreement with CS show a more self-oriented and petitionary religiosity, in which God is seen as especially interested in and responsive to them. And they tend to pray for divine assistance to meet their personal wants. In contrast, controlling for CS sentiment, believers with stronger RT agreement express a more praise-oriented and confessional religiosity, in which they feel personally accountable for their sins and routinely ask for forgiveness. RT believers also view God as more concerned with the well-being of the whole world and are less likely to ask for personal blessings. These findings further indicate that CS believers tend to express an individualized religiosity and that RT believers are more likely to spread faith and praise God.

The commons have emerged as a key notion and underlying experience of many efforts around the world to promote justice and democracy. A central question for political theories of the commons is whether the visions of social order and regimes of political economy they propose are complementary or opposed to public goods that are backed up by governmental coordination and compulsion. This essay argues that the post-Marxist view, which posits an inherent opposition between the commons as a sphere of inappropriable usage and statist public infrastructure, is mistaken, because justice and democracy are not necessarily furthered by the institution of inappropriability. I articulate an alternative pluralist view based on James Tully’s work, which discloses the dynamic interplay between public and common modes of provision and enjoyment, and their civil and civic orientations respectively. Finally, the essay points to the Janus-faced character of the commons and stresses the co-constitutive role of public goods and social services for just and orderly social life while remaining attentive to the dialectic of empowerment and tutelage that marks provision by government.

Since the early 2000s, many of the left groups that spurred the alt-globalization movement have embraced directly democratic organizing and the creation of ethical relationships and subjectivities far more than they have pursued projects to reform legal and political institutions. These practices are often described as prefigurative because people are working to build alternative possible futures in the here-and-now outside of dominant statist and capitalist rationalities. In this essay, we ask if prefiguration can also involve imagining legal forms anew. Drawing on Amelia Thorpe, Owning the Street: The Everyday Life of Property (2020), we discuss contemporary efforts to use the language, form, and legitimacy of law to imagine it otherwise, efforts that occur through various kinds of direct actions rather than primarily through appeals to courts, legislators, or other state officials. In so doing, we point to an emergent field of critical and sociolegal scholarship that we call prefigurative legality.

Reproducibility is imperative for any scientific discovery. More often than not, modern scientific findings rely on statistical analysis of high-dimensional data. At a minimum, reproducibility manifests itself in stability of statistical results relative to \"reasonable\" perturbations to data and to the model used. Jacknife, bootstrap, and cross-validation are based on perturbations to data, while robust statistics methods deal with perturbations to models. In this article, a case is made for the importance of stability in statistics. Firstly, we motivate the necessity of stability for interpretable and reliable encoding models from brain fMRI signals. Secondly, we find strong evidence in the literature to demonstrate the central role of stability in statistical inference, such as sensitivity analysis and effect detection. Thirdly, a smoothing parameter selector based on estimation stability (ES), ES-CV, is proposed for Lasso, in order to bring stability to bear on cross-validation (CV). ES-CV is then utilized in the encoding models to reduce the number of predictors by 60% with almost no loss (1.3%) of prediction performance across over 2,000 voxels. Last, a novel \"stability\" argument is seen to drive new results that shed light on the intriguing interactions between sample to sample variability and heavier tail error distribution (e.g., double-exponential) in high-dimensional regression models with p predictors and n independent samples. In particular, when p/n → κ ∈ (0.3, 1) and the error distribution is double-exponential, the Ordinary Least Squares (OLS) is a better estimator than the Least Absolute Deviation (LAD) estimator.

We propose a method for constructing p-values for general hypotheses in a high-dimensional linear model. The hypotheses can be local for testing a single regression parameter or they may be more global involving several up to all parameters. Furthermore, when considering many hypotheses, we show how to adjust for multiple testing taking dependence among the p-values into account. Our technique is based on Ridge estimation with an additional correction term due to a substantial projection bias in high dimensions. We prove strong error control for our p-values and provide sufficient conditions for detection: for the former, we do not make any assumption on the size of the true underlying regression coefficients while regarding the latter, our procedure might not be optimal in terms of power. We demonstrate the method in simulated examples and a real data application.

Public diplomacy (PD) lacks an agreed-upon definition and boundaries. The ambiguity surrounding the conceptualization of the term leads to confusion among scholars and practitioners and hinders the consolidation of PD as an academic field. This article surveys 160 articles and books on PD, categorizes diverse perspectives into a taxonomy, and explores the coherence of each. The taxonomy can be categorized into these perspectives: state-centric, neo-statist, nontraditional, society-centric, and accommodative. The article maps the boundaries of public diplomacy with much needed clear and coherent criteria and positions PD within the broader discipline of international relations. Una definición y límites consensuados es lo que le falta a la diplomacia pública (DP). La ambigüedad del término confunde tanto a académicos como a profesionales, y dificulta la consolidación de la DP como un área de estudio académico. Este trabajo analiza 160 artículos y libros sobre DP, clasifica las distintas perspectivas y explora la coherencia de cada una de ellas. Dicha clasificación incluye las siguientes perspectivas: centrado en el Estado, neoestatismo, no tradicional, centrado en la sociedad y acomodativa. El artículo define los límites de la diplomacia pública mediante criterios claros, coherentes y necesarios, y posiciona a la DP en la disciplina de relaciones internacionales, la cual es más amplia. La diplomatie publique (DP) est dépourvue de consensus quant à sa définition et à sa délimitation. L’ambiguïté dont est empreinte la conceptualisation du terme amène à une confusion parmi les universitaires et les praticiens et empêche la consolidation de la DP en tant que domaine académique. Le présent article est une étude de 160 articles et ouvrages sur la DP, il établit une taxonomie des différentes perspectives diplomatiques et explore la cohérence de chacune d’elles. Les perspectives réunies au sein de cette taxonomie sont les suivantes : école centrée sur l’état, école néo-étatiste, école non traditionnelle, école centrée sur la société et école accommodante. L’article propose une délimitation de la diplomatie publique à l’aide de critères dont la clarté et la cohérence étaient très attendues – et positionne la DP au sein de la discipline élargie des relations internationales.