Laboratory experiments are frequently used to examine the nature of individuals’ social and risk preferences and inform economic theory. However, it is unknown whether the preferences of volunteer participants are representative of the population from which the participants are drawn, or whether they differ due to selection bias. To answer this question, we measured the preferences of 1,173 students in a classroom experiment using a trust game and a lottery choice task. Separately, we invited all students to participate in a laboratory experiment using common recruitment procedures. To evaluate whether there is selection bias, we compare the social and risk preferences of students who eventually participated in a laboratory experiment to those who did not, and find that they do not differ significantly. However, we also find that people who sent less in a trust game were more likely to participate in a laboratory experiment, and discuss possible explanations for this behavior.

The Magellanic Stream (MS), a tail of diffuse gas formed from tidal and ram pressure interactions between the Small and Large Magellanic Clouds (SMC and LMC) and the Halo of the Milky Way, is primarily composed of neutral atomic hydrogen (HI). The deficiency of dust and the diffuse nature of the present gas make molecular formation rare and difficult, but if present, could lead to regions potentially suitable for star formation, thereby allowing us to probe conditions of star formation similar to those at high redshifts. We search for $\text{HCO}^{+}$, HCN, HNC, and C$_2$H using the highest sensitivity observations of molecular absorption data from the Atacama Large Millimeter Array (ALMA) to trace these regions, comparing with HI archival data from the Galactic Arecibo L-Band Feed Array (GALFA) HI Survey and the Galactic All Sky Survey (GASS) to compare these environments in the MS to the HI column density threshold for molecular formation in the Milky Way. We also compare the line of sight locations with confirmed locations of stars, molecular hydrogen, and OI detections, though at higher sensitivities than the observations presented here.

We find no detections to a 3$\sigma$ significance, despite four sightlines having column densities surpassing the threshold for molecular formation in the diffuse regions of the Milky Way. Here we present our calculations for the upper limits of the column densities of each of these molecular absorption lines, ranging from $3 \times 10^{10}$ to $1 \times 10^{13}$ cm$^{-2}$. The non-detection of $\text{HCO}^{+}$ suggests that at least one of the following is true: (i) $X_{\text{HCO}^{+}{}, \mathrm{MS}}$ is significantly lower than the Milky Way value; (ii) that the widespread diffuse molecular gas observed by Rybarczyk (2022b, ApJ, 928, 79) in the Milky Way’s diffuse interstellar medium (ISM) does not have a direct analogue in the MS; (iii) the HI-to-$\text{H}_{2}$ transition occurs in the MS at a higher surface density in the MS than in the LMC or SMC; or (iv) molecular gas exists in the MS, but only in small, dense clumps.

This article introduces and demonstrates the utility of a new event dataset on democratic erosion around the world. Through case studies of Turkey and Brazil, we show that our Democratic Erosion Event Dataset (DEED) can help to resolve debates about the extent to which democracy is backsliding based on prominent cross-national indicators, focusing in particular on the Varieties of Democracy (V-Dem) and Little and Meng (L&M) indices. V-Dem suggests that democracies are deteriorating worldwide; L&M argue that this may be an artifact of subjectivity and coder bias and that more “objective” indicators reveal little to no global democratic backsliding in recent years. Using DEED, we show that—at least in these cases—objective indices may underestimate the extent of democratic erosion whereas subjective indices may overestimate it. Our analyses illustrate the ways in which DEED can complement existing indices by illuminating the nature and dynamics of democratic erosion as it occurs on the ground.

Does UN peacekeeping promote democracy in countries wracked by civil war? Existing studies are limited and reach contradictory conclusions. We develop a theory to explain how peacekeepers can help overcome obstacles to democratization in conflict-affected countries, then test our theory by combining three original datasets on UN mandates, personnel, and activities covering all UN missions in Africa since the end of the Cold War. Using fixed effects and instrumental variables estimators, we show that UN missions with democracy promotion mandates are strongly positively correlated with the quality of democracy in host countries but that the magnitude of the relationship is larger for civilian than for uniformed personnel, stronger when peacekeepers engage rather than bypass host governments when implementing reforms, driven in particular by UN election administration and oversight, and more robust during periods of peace than during periods of civil war.

How can states prevent armed groups from exploiting local governance gaps to (re)establish territorial control during transitions to national peace? We report results from an experimental evaluation of Colombia’s ComunPaz program, a scalable, inexpensive intervention that sought to replace rebel governance by harnessing complementarities between state and communal authorities and by improving security and justice provision in areas once dominated by FARC, the country’s largest rebel group. We find that ComunPaz enhanced the quality of local dispute resolution, increased citizens’ trust in (some) state institutions, and strengthened coordination between state and communal authorities. It also appears to have reduced citizens’ trust in, and reliance on, armed groups. The program did not, however, increase reliance on either state or communal authorities to resolve disputes, nor did it increase citizens’ trust in communal institutions. We discuss the implications of our findings for peace-building and state-building in countries transitioning from civil war.

Is foreign aid an effective instrument of soft power? Does it generate affinity for donor countries and the values they espouse? This article answers these questions in the context of Chinese aid to Africa and the competing aid regime of the United States. The study combines data on thirty-eight African countries from Afrobarometer, AidData, and the Aid Information Management Systems of African finance and planning ministries. The authors use spatial difference-in-differences to isolate the causal effects of Chinese and US aid. The study finds that Chinese aid to Africa does not increase (and may in fact reduce) beneficiaries’ support for China. By contrast, US aid appears to increase support for the United States and to strengthen recipients’ commitment to liberal democratic values, such as the belief in the importance of elections. Chinese aid does not appear to weaken this commitment, and may strengthen it. The study also finds that Chinese aid increases support for the UK, France and other former colonial powers. These findings advance our understanding of the conditions under which competing aid regimes generate soft power and facilitate the transmission of political principles and ideals.

ABSTRACT IMPACT: Many who suffer from end-stage organ disease do not qualify for solid organ transplantation because of obesity; however, bariatric surgery offers the potential to render select patients transplant-eligible, and in some cases, may lead to weight loss that is sufficient to reverse end-stage organ disease. OBJECTIVES/GOALS: As obesity prevalence grows, more end-stage organ disease patients will be precluded from transplant. Numerous reports suggest bariatric surgery in end-stage organ disease may help patients achieve weight loss sufficient for transplant listing, though the published data are limited. METHODS/STUDY POPULATION: We performed a systematic review/meta-analysis of studies of bariatric surgery to achieve solid organ transplant listing. RESULTS/ANTICIPATED RESULTS: Among 82 heart failure patients, 40.2% lost sufficient weight for listing, 29.3% were transplanted, and 8.5% had sufficient improvement with weight loss they no longer required transplantation. Among 28 end-stage lung disease patients, 28.6% lost sufficient weight for listing, 7.1% were transplanted, and 14.3% had sufficient improvement following weight loss they no longer required transplant. Among 41 cirrhosis patients, 58.5% lost sufficient weight for listing, 41.5% were transplanted, and 21.9% had sufficient improvement following weight loss they no longer required transplant. Among 288 end-stage/chronic kidney disease patients, 50.3% lost sufficient weight for listing and 29.5% were transplanted. DISCUSSION/SIGNIFICANCE OF FINDINGS: Small sample size and publication bias are limitations; however, bariatric surgery may benefit select end-stage organ disease patients with obesity that precludes transplant candidacy.

What are the effects of foreign aid on the perceived legitimacy of recipient states? Different donors adhere to different rules, principles, and operating procedures. The authors theorize that variation in these aid regimes may generate variation in the effects of aid on state legitimacy. To test their theory, they compare aid from the United States to aid from China, its most prominent geopolitical rival. Their research design combines within-country analysis of original surveys, survey experiments, and behavioral games in Liberia with cross-country analysis of existing administrative and Afrobarometer data from six African countries. They exploit multiple proxies for state legitimacy, but focus in particular on tax compliance and morale. Contrary to expectations, the authors find little evidence to suggest that exposure to aid diminishes the legitimacy of African states. If anything, the opposite appears to be true. Their results are consistent across multiple settings, multiple levels of analysis, and multiple measurement and identification strategies, and are unlikely to be artifacts of sample selection, statistical power, or the strength or weakness of particular experimental treatments. The authors conclude that the effects of aid on state legitimacy at the microlevel are largely benign.

How does violence during civil war shape citizens' demand for state-provided security, especially in settings where non-state actors compete with the state for citizens' loyalties? This article draws on Hobbesian theory to argue that in post-conflict countries, citizens who were more severely victimized by wartime violence should substitute away from localized authorities and towards centralized ones, especially the state. The author tests the theory by combining two original surveys with existing media and non-governmental organization data on wartime violence in Liberia. The study shows that citizens who were more severely affected by violence during the Liberian civil war are more likely to demand state-provided security, both in absolute terms and relative to non-state alternatives. More sporadic collective violence in the post-conflict period does not reverse this substitution effect. Also consistent with Hobbesian theory, citizens who were more severely victimized are more fearful of threats to peace almost a decade later.