Sensitivity Analysis for Multiple Comparisons in Matched Observational Studies through Quadratically Constrained Linear Programming

A sensitivity analysis in an observational study assesses the robustness of significant findings to unmeasured confounding. While sensitivity analyses in matched observational studies have been well addressed when there is a single outcome variable, accounting for multiple comparisons through the existing methods yields overly conservative results when there are multiple outcome variables of interest. This stems from the fact that unmeasured confounding cannot affect the probability of assignment to treatment differently depending on the outcome being analyzed. Existing methods allow this to occur by combining the results of individual sensitivity analyses to assess whether at least one hypothesis is significant, which in turn results in an overly pessimistic assessment of a study's sensitivity to unobserved biases. By solving a quadratically constrained linear program, we are able to perform a sensitivity analysis while enforcing that unmeasured confounding must have the same impact on the treatment assignment probabilities across outcomes for each individual in the study. We show that this allows for uniform improvements in the power of a sensitivity analysis not only for testing the overall null of no effect, but also for null hypotheses on \textit{specific} outcome variables while strongly controlling the familywise error rate. We illustrate our method through an observational study on the effect of smoking on naphthalene exposure

Selecting the Best? Spillover and Shadows in Elimination Tournaments

We consider how past, current, and future competition within an elimination tournament affect the probability that the stronger player wins. We present a two-stage model that yields the following main results: (1) a shadow effect—the stronger the expected future competitor, the lower the probability that the stronger player wins in the current stage and (2) an effort spillover effect—previous effort reduces the probability that the stronger player wins in the current stage. We test our theory predictions using data from high-stakes tournaments. Empirical results suggest that shadow and spillover effects influence match outcomes and have been already been priced into betting markets.

Fluctuations in Mass-Action Equilibrium of Protein Binding Networks

We consider two types of fluctuations in the mass-action equilibrium in protein binding networks. The first type is driven by relatively slow changes in total concentrations (copy numbers) of interacting proteins. The second type, to which we refer to as spontaneous, is caused by quickly decaying thermodynamic deviations away from the equilibrium of the system. As such they are amenable to methods of equilibrium statistical mechanics used in our study. We investigate the effects of network connectivity on these fluctuations and compare them to their upper and lower bounds. The collective effects are shown to sometimes lead to large power-law distributed amplification of spontaneous fluctuations as compared to the expectation for isolated dimers. As a consequence of this, the strength of both types of fluctuations is positively correlated with the overall network connectivity of proteins forming the complex. On the other hand, the relative amplitude of fluctuations is negatively correlated with the abundance of the complex. Our general findings are illustrated using a real network of protein-protein interactions in baker's yeast with experimentally determined protein concentrations.Comment: 4 pages, 3 figure

The California Supreme Court’s Unlawful Use of Legislative History to Interpret Unambiguous Statutes during Its 2005 Term

A large part of the California Supreme Court’s job is to interpret the statutes that the California Legislature has enacted. The Court has developed clear rules for this task. One of the rules is that courts may rely on legislative history if and only if the statute being interpreted is ambiguous. However, as a review of the Court’s recent Term from September 2005 to August 2006 reveals, the Court consistently violates this important rule. This article considers four cases in which the Court used legislative history to “confirm” the meaning of an unambiguous statute, and one case in which the Court used legislative history to change an unambiguous statute’s meaning. It concludes with suggestions for improving the Court’s performance

Occupy This: The Effect of Income Inequality on GDP Per Capita Growth Using Panel Data in the United States from 1963 to 2009

Income inequality and its relationship to long-term GDP per capita growth has been researched for decades since the development of the Kuznet’s Curve. Theoretical and empirical research has shown mixed results including positive, negative, non-existent, or statistically insignificant relationships. Empirical research on income inequality and economic growth in the United States has also shown mixed results. In addition to using existing data, this paper uses originally-constructed Gini Coefficients from 2005 to 2009. A statistically significant negative correlation between income inequality, and both short-term growth and long-term growth is found in the analysis of this data. Finally, this paper attempts to justify a causal relationship between income inequality and long-term growth

Composing Citizens: Epistemic Work in the Interstices of Comprehensive- Planning Genre Systems

This case-study examines the ways citizens took up, and in some ways resisted, city planners’ assumptions about their lived experience of “Portstown.” While it is necessary to acknowledge the coercive properties of institutional documents and genre-systems, community-literacy workers must not efface the epistemic potential of everyday compositions, for this quality creates opportunities for strategic interventions in the solicitation and reception of civic writing

Book Review: Fighting For Honor: The History of African Martial Arts in the Atlantic World

Dylan McElroy reviews Fighting for Honor: A History of African Martial Art Traditions in the Atlantic World, written by T. J. Desch-Obi