2,617 research outputs found

    A central limit theorem for the Benjamini-Hochberg false discovery proportion under a factor model

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    The Benjamini-Hochberg (BH) procedure remains widely popular despite having limited theoretical guarantees in the commonly encountered scenario of correlated test statistics. Of particular concern is the possibility that the method could exhibit bursty behavior, meaning that it might typically yield no false discoveries while occasionally yielding both a large number of false discoveries and a false discovery proportion (FDP) that far exceeds its own well controlled mean. In this paper, we investigate which test statistic correlation structures lead to bursty behavior and which ones lead to well controlled FDPs. To this end, we develop a central limit theorem for the FDP in a multiple testing setup where the test statistic correlations can be either short-range or long-range as well as either weak or strong. The theorem and our simulations from a data-driven factor model suggest that the BH procedure exhibits severe burstiness when the test statistics have many strong, long-range correlations, but does not otherwise.Comment: Main changes in version 2: i) restated Corollary 1 in a way that is clearer and easier to use, ii) removed a regularity condition for our theorems (in particular we removed Condition 2 from version 1), and iii) we added a couple of remarks (namely, Remark 1 and 6 in version 2). Throughout the text we also fixed typos, improved clarity, and added a some additional commentary and reference

    Tie-breaker designs provide more efficient kernel estimates than regression discontinuity designs

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    Tie-breaker experimental designs are hybrids of Randomized Controlled Trials (RCTs) and Regression Discontinuity Designs (RDDs) in which subjects with moderate scores are placed in an RCT while subjects with extreme scores are deterministically assigned to the treatment or control group. The tie-breaker design (TBD) has practical advantages over the RCT in settings where it is unfair or uneconomical to deny the treatment to the most deserving recipients. Meanwhile, the TBD has statistical benefits due to randomization over the RDD. In this paper we discuss and quantify the statistical benefits of the TBD compared to the RDD. If the goal is estimation of the average treatment effect or the treatment at more than one score value, the statistical benefits of using a TBD over an RDD are apparent. If the goal is estimation of the average treatment effect at merely one score value, which is typically done by fitting local linear regressions, about 2.8 times more subjects are needed for an RDD in order to achieve the same asymptotic mean squared error. We further demonstrate using both theoretical results and simulations from the Angrist and Lavy (1999) classroom size dataset, that larger experimental radii choices for the TBD lead to greater statistical efficiency.Comment: This version is quite different than version 1. We have added an analysis when the bandwidth is shrinking with the sample size. We have also added a discussion of other statistical advantages of a TBD compared to an RD

    The UN War Crimes Commission and International Law: Revisiting World War II Precedents and Practice

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    The history of international legal institutions has largely ignored the early activities of the United Nations, specifically of the UN War Crimes Commission (UNWCC). Based on an assessment of its work and with access to new archival evidence, contemporary international legal institutional design could benefit significantly from revisiting the commission’s achievements, particularly the principle of complementarity identified in the Rome Statute of the International Criminal Court, and support for domestic tribunals for war crimes and crimes against humanity. The article begins by examining the history, multilateral basis for, and practical activities of the commission. Subsequently, it assesses its contemporary relevance. Finally, it analyses—with reference to modern literature on complementarity—the degree to which the commission’s wartime model provides positive examples of implementation of the principle that could be replicated today, with particular reference to domestic capacity-building and international coordination

    Geothermal Development and Western Water Law

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    Biases in estimates of air pollution impacts: the role of omitted variables and measurement errors

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    Observational studies often use linear regression to assess the effect of ambient air pollution on outcomes of interest, such as human health outcomes or crop yields. Yet pollution datasets are typically noisy and include only a subset of potentially relevant pollutants, giving rise to both measurement error bias (MEB) and omitted variable bias (OVB). While it is well understood that these biases exist, less is understood about whether these biases tend to be positive or negative, even though it is sometimes falsely claimed that measurement error simply biases regression coefficient estimates towards zero. In this paper, we show that more can be said about the direction of these biases under the realistic assumptions that the concentrations of different types of air pollutants are positively correlated with each other and that each type of pollutant has a nonpositive association with the outcome variable. In particular, we demonstrate both theoretically and using simulations that under these two assumptions, the OVB will typically be negative and that more often than not the MEB for null pollutants or for pollutants that are perfectly measured will be negative. We also provide precise conditions, which are consistent with the assumptions, under which we prove that the biases are guaranteed to be negative. While the discussion in this paper is motivated by studies assessing the effect of air pollutants on crop yields, the findings are also relevant to regression-based studies assessing the effect of air pollutants on human health outcomes

    Addressing contingency in algorithmic (mis)information classification: Toward a responsible machine learning agenda

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    Machine learning (ML) enabled classification models are becoming increasingly popular for tackling the sheer volume and speed of online misinformation and other content that could be identified as harmful. In building these models, data scientists need to take a stance on the legitimacy, authoritativeness and objectivity of the sources of ``truth" used for model training and testing. This has political, ethical and epistemic implications which are rarely addressed in technical papers. Despite (and due to) their reported high accuracy and performance, ML-driven moderation systems have the potential to shape online public debate and create downstream negative impacts such as undue censorship and the reinforcing of false beliefs. Using collaborative ethnography and theoretical insights from social studies of science and expertise, we offer a critical analysis of the process of building ML models for (mis)information classification: we identify a series of algorithmic contingencies--key moments during model development that could lead to different future outcomes, uncertainty and harmful effects as these tools are deployed by social media platforms. We conclude by offering a tentative path toward reflexive and responsible development of ML tools for moderating misinformation and other harmful content online.Comment: Andr\'es Dom\'inguez Hern\'andez, Richard Owen, Dan Saattrup Nielsen and Ryan McConville. 2023. Addressing contingency in algorithmic (mis)information classification: Toward a responsible machine learning agenda. Accepted in 2023 ACM Conference on Fairness, Accountability, and Transparency (FAccT '23), June 12-15, 2023, Chicago, United States of America. ACM, New York, NY, USA, 16 page
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