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Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ∼0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ∼2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ∼75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.

The timing and abruptness of the initiation and termination of the Early Holocene African Humid Period are subjects of ongoing debate, with direct consequences for our understanding of abrupt climate change, paleoenvironments, and early human cultural development. Here, we provide proxy evidence from the Horn of Africa region that documents abrupt transitions into and out of the African Humid Period in northeast Africa. Similar and generally synchronous abrupt transitions at other East African sites suggest that rapid shifts in hydroclimate are a regionally coherent feature. Our analysis suggests that the termination of the African Humid Period in the Horn of Africa occurred within centuries, underscoring the nonlinearity of the region's hydroclimate.

We estimate how the marginal utility of consumption varies with health. To do so, we develop a simple model in which the impact of health on the marginal utility of consumption can be estimated from data on permanent income, health, and utility proxies. We estimate the model using the Health and Retirement Study's panel data on the elderly and near-elderly, and proxy for utility with measures of subjective well-being. Across a wide range of alternative specifications and assumptions, we find that the marginal utility of consumption declines as health deteriorates, and we are able to clearly reject the null of no state dependence. Our point estimates indicate that a one-standard-deviation increase in the number of chronic diseases is associated with a 10%—25% decline in the marginal utility of consumption relative to this marginal utility when the individual has no chronic diseases. We present some simple, illustrative calibration results that suggest that state dependence of the magnitude we estimate can have a substantial effect on important economic problems such as the optimal level of health insurance benefits and the optimal level of life-cycle savings.

We investigate whether politically sensitive contractors pay higher taxes and whether their bargaining power reduces these tax costs. Using federal contractor data, we develop a new composite measure of political sensitivity that captures both the political visibility arising from federal contracts and the importance of federal contracts to the firm. We proxy for bargaining power using the firm-level proportion of contract revenues not subject to competition, the firm-level proportion of contract revenues arising from defense contracts, and industry-level concentration ratios. We find that politically sensitive firms pay higher federal taxes, all else equal. However, firms with greater bargaining power incur fewer tax-related political costs. Our study provides new evidence on the political cost hypothesis in a tax setting and the first evidence of the interactive effects of a firm's political sensitivity and bargaining power on tax-related political costs.

Social comparison consists of comparing oneself with others in order to evaluate or to enhance some aspects of the self. Evaluation of ability is concerned with the question \"Can I do X?\" and relies on the existence of a proxy performer. A proxy's relative standing on attributes vis-à-vis the comparer and whether the proxy exerted maximum effort on a preliminary task are variables influencing his or her informational utility. Evaluation of opinions is concerned with the questions \"Do I like X?\" Is X correct?\" and \"Will I like X?\" Important variables that affect an individual's use of social comparison to evaluate hisor her opinions are the other person's expertise, similarity with the individual, and previous agreement with the individual. Whether social comparison serves a self-enhancement function depends on whether the comparer assimilates or contrasts his or her self relative to superior or inferrior others. The kinds of self-knowledge made cognitively accessible and variables such as mutability of self-views and distinctiveness of the comparison target may be important determinants of assimilation versus contrast.

A popular proxy for gun ownership is the fraction of suicides from firearms. This has made identifying the causal effect of guns on suicide difficult. In this article, firearm background checks are used as a proxy for changes in gun ownership rates, allowing the effect of guns on suicide to be identified. The results from panel data regressions show that increases in firearm background checks rates are associated with increases in firearm suicide rates. Overall suicide is positively, but insignificantly, related to background checks. To alleviate endogeneity that comes from suicidal individuals purchasing a gun to commit suicide, youth suicide is analysed and yields similar, but noisier results.

The internet contains billions of documents. We show that document frequencies in large decentralized textual databases can capture the cross-sectional variation in the occurrence frequencies of social phenomena. We characterize the econometric conditions under which such proxying is likely. We also propose using recently-introduced internet search volume indexes as proxies for fundamental locational traits, and discuss their advantages and limitations. We then successfully proxy for a number of economic and demographic variables in US cities and states. We further obtain document-frequency measures of corruption by country and US state and replicate the econometric results of previous research studying its covariates. Finally, we provide the first measure of corruption in American cities. Poverty, population size, service-sector orientation, and ethnic fragmentation are shown to predict higher levels of corruption in urban America.

We uncover a strong comovement of the stock market risk—return trade-off with the consumption—wealth ratio (CAY). The finding reflects time-varying investment opportunities rather than countercyclical aggregate relative risk aversion. Specifically, the partial risk—return trade-off is positive and constant when we control for CAY as a proxy for investment opportunities. Moreover, conditional market variance scaled by CAY is negatively priced in the cross-section of stock returns. Our results are consistent with a limited stock market participation model, in which shareholders require an illiquidity premium that increases with CAY, in addition to the risk premium that is proportional to conditional market variance.

Researchers often recruit proxy respondents, such as relatives or caregivers, for epidemiologic studies of older adults when study participants are unable to provide self-reports (eg, because of illness or cognitive impairment). In most studies involving proxy-reported outcomes, proxies are recruited only to report on behalf of participants who have missing self-reported outcomes; thus, either a proxy report or participant self-report, but not both, is available for each participant. When outcomes are binary and investigators conceptualize participant self-reports as gold standard measures, substituting proxy reports in place of missing participant self-reports in statistical analysis can introduce misclassification error and lead to biased parameter estimates. However, excluding observations from participants with missing self-reported outcomes may also lead to bias. We propose a pattern-mixture model that uses error-prone proxy reports to reduce selection bias from missing outcomes, and we describe a sensitivity analysis to address bias from differential outcome misclassification. We perform model estimation with high-dimensional (eg, continuous) covariates using propensity-score stratification and multiple imputation. We apply the methods to the Second Cohort of the Baltimore Hip Studies, a study of elderly hip fracture patients, to assess the relation between type of surgical treatment and perceived physical recovery. Simulation studies show that the proposed methods perform well. We provide SAS programs in the eAppendix (http://links.lww.com/EDE/A646) to enhance the methods' accessibility.

Background: The rate of readmission is widely used as a measure of hospital quality of care, often with funding implications for outlying facilities. Objectives: This study explored the plausibility of readmission as a proxy for health care quality with quantitative bias analysis and the application of a structural Directed Acyclic Graph framework. It applies this paradigm to observed ethnic differences in the odds of readmission in a sample of New Zealand hospital patients. Research Design: Ethnicity was defined as the exposure, readmission rate as the proxy outcome, and quality of care as a missing mediator. Using data from 89,090 surgical patients from New Zealand, and estimates from the literature of the prevalence of \"poor quality\" and the strength of the quality-of-care readmission association, a series of sensitivity analyses were performed to calculate an odds ratio of the ethnicity-readmission association corrected for the missing mediator \"quality.\" Results: Given the assumptions applied, potentially only 29% of the excess odds of readmission for Māori compared with Europeans were due to poor quality of care. Conclusions: This investigation finds substantial error when using readmission as a marker of quality, and suggests that differences in readmission between populations are more likely to be due to factors other than quality of care.