In many situations people behave ethically, while elsewhere dishonesty reigns. Studies of the determinants of unethical behavior often use random assignment of participants in various conditions to identify contextual or psychological factors influencing dishonesty. However, in many real-world contexts, people deliberately choose or avoid specific environments. In three experiments (total N = 2,124) enabling self-selection of participants in two similar tasks, one of which allowed for cheating, we found that participants who chose the task where they could lie for financial gain reported a higher number of correct predictions than those who were assigned it at random. Introduction of financial costs for entering the cheating-allowing task led to a decrease in interest in the task; however, it also led to more intense cheating. An intervention aimed to discourage participants from choosing the cheating-enabling environment based on social norm information did not have the expected effect; on the contrary, it backfired. In summary, the results suggest that people low in moral character are likely to eventually dominate cheating-enabling environments, where they then cheat extensively. Interventions trying to limit the preference of this environment may not have the expected effect as they could lead to the selection of the worst fraudsters.

The dynamics of choice and self-selection are central features of politics but absent from most experimental designs. We show how designs that incorporate choice, by allowing some subjects the option to receive or avoid treatment, can be extended by randomizing conditional on subjects’ treatment choices to answer further questions of interest while preserving statistical power. We apply this design to study how the gender of messengers for the #MeToo social movement conditions who receives the movement’s message and how they respond. Our results, from both convenience and nationally representative samples, suggest that #MeToo movement’s message reaches a wide audience with the intended effect. The potential for backlash in response to the message appears limited but more likely when this message is delivered by a woman.

This paper introduces an instrumental variables framework for analyzing how external factors that affect survey response rates can also affect the composition of the sample of respondents. The method may be useful for studying survey representativeness, and for assessing the effectiveness of some of the conventional corrections for survey nonresponse bias.

The paper applies the method to data collected in the 2011 Swiss Electoral Study (SES), in which survey participation incentives were randomly assigned across members of the original survey sample. The empirical analysis shows that the incentives increased response rates substantially. Estimates of a new instrumental variable parameter called the Complier Average Survey Response (CASR) suggest that the incentives induced participation among people with more nationalist political opinions than those who would have participated without the incentives. Weighting the respondent data to match the covariate distribution in the target population did not account for the discrepancy in attitudes between the two groups, suggesting that the weights would not succeed in removing nonresponse bias.

Our research investigates the effects of residential energy efficiency audit programs on subsequent household electricity consumption. Here there is a one-time interaction between households, which participate voluntarily, and the surveyors. Our research objective is to determine whether and to what extent the surveys lead to behavioral changes. We then examine how persistent the intervention is over time and whether the effects decay or intensify. The main evaluation problem here is survey participants’ self-selection, which we address econometrically via several non-parametric estimators involving kernel-based propensity-score matching. In the first method we use difference-in-differences (DID) estimation. Our second estimator is quantile DID, which produces estimates on distributions. The comparison group consists of households who were not yet participating in the survey but participated later. Our evidence is that the customers who participated in the survey reduced their electricity consumption by about 7%, on average compared to customers who had not yet participated in the survey. Considering the total number of high-usage households participating in the survey in 2009, we estimate that electricity consumption was reduced by an aggregate of 2 million kWh per year, which is approximately equal to the monthly consumption of 3500 typical households in California with an estimated 1527 metric tons less of carbon dioxide emissions. Because the energy audit program is inexpensive ($10–$20 per household) a key issue is that while the program is cost-effective, is it regressive? We find that as the quantiles of the outcome distribution increase, high-use households save proportionally less electricity than do low-use customers. Overall, our results imply that program designers can better target low-use and low-income households, because they are more likely to benefit from the programs through energy savings.

Ecological validity is vital to experimental research because designs that are too artificial may not speak to any real-world political phenomenon. One such concern is treatment of self-selection: if individuals in the real-world self-select treatments, such as political communications, how well does the sample average treatment effect estimate the effects of message exposure for those individuals who would—if given the choice—opt-in to and out of receiving treatment? This study shows that randomization masks effect heterogeneity between individuals who would select different messages if given the choice. Yet, such selections are themselves complex, revealing additional challenges for realistically studying treatments prone to self-selection. The evidence of effect heterogeneity raises questions about the appropriateness of random assignment experiments for studying political communication and the results more broadly advance our understanding of citizens’ selection into and responses to communications when, as they often do, have choice over what messages to receive.

The impact of adopting integrated pest management (IPM) techniques is examined for peach producers in eight states accounting for most of the U.S. production. The method accounts for self-selectivity, simultaneity, and the pesticide demand equations are theoretically consistent with a restricted-profit function. Biological pest management techniques tend to reduce pesticide use and pesticide toxicity substantially, while pesticide-efficiency techniques (using scouting and economic thresholds) have an increasing effect on pesticide use and toxicity, and cultural techniques have an insignificant effect on pesticide use and toxicity.

In light of the declining pension coverage of low-income workers, policy makers have discussed requiring all employers to offer individual retirement accounts, similar to defined contribution plans. How likely to participate are workers who currently do not have access to a pension plan? We address this question by using plausibly exogenous variation in pension-plan availability to estimate the determinants of participation in a standard selection on unobservables model. We find that currently uncovered low-income workers are fairly likely to participate in a newly offered plan, yet they are much less likely to do so than currently covered workers.

Heat stress can induce hyperthermia in poultry. A reduction in heat load can be achieved by increasing the possibilities for dissipation, decreasing the level of heat production or by changing the thermal production pattern within a day. Strategies to reduce the negative effects of heat stress can be based on a specific feeding strategy, such as restricted feeding. Feed that is offered long enough before a hot period can ameliorate the harmful effects of high temperature. Another strategy may be to use choice feeding from different feed ingredients, rich in protein or in energy. With such self-selection, the chicken may adjust its intake of individual components, allowing the bird to optimise the heat load associated with the metabolism of the ingested nutrients. Additional promising strategies involve offering a choice between feeds with a different feed particle size or structure. A large particle size contributes to the development of the gastro-intestinal tract (GIT), especially the gizzard and the caeca. A large gizzard will maximize the grinding process and potentially ease digestion down the GIT, thereby reducing heat production associated with digestive processing. Also wet feeding may be profitable under heat stress conditions as well. Feeding wet diets may facilitate an increased water intake and larger particle sizes can limit water excretion in droppings, resulting in more water being available for evaporation during panting, hence cooling the bird. In conclusion, these feeding strategies may help to reduce heat production peaks, facilitate evaporative activity and/or decreases the heat load, resulting in beneficial effects on performance and health of the bird kept in more tropical areas worldwide.

This paper evaluates two well-known models of growth with inequality that have explicit micro underpinnings related to household choice. With incomplete markets or transactions costs, wealth can constrain investment in business and the choice of occupation and also constrain the timing of entry into the formal financial sector. Using the Thai Socio-Economic Survey (SES), we estimate the distribution of wealth and the key parameters that best fit cross-sectional data on household choices and wealth. We then simulate the model economies for two decades at the estimated initial wealth distribution and analyze whether the model economies at those micro-fit parameter estimates can explain the observed macro and sectoral aspects of income growth and inequality change. Both models capture important features of Thai reality. Anomalies and comparisons across the two distinct models yield specific suggestions for improved research on the micro foundations of growth and inequality.

Corn and soyabeans may not be available in many countries particularly those which do not have sufficient foreign currency or the capacity to grow them. This paper outlines strategies that may be important under these circumstances. Alternative feedstuffs and various feeding systems may be used to support poultry production. Alternative ingredients such as rice bran, pearl millet, cottonseed meal and grain legumes are discussed. Evidence is presented showing that amino acid requirements of layers and broilers may be too generous particularly in countries where climate, management and disease can impose production constraints. The ability of finishing broilers to perform well on very low-energy diets allows the inclusion of alternative feeds and by-products into formulations. Very low protein diets based on cereals and free amino acids can be used for layers without loss of performance. Self-selection of feedstuffs may be an important strategy in reducing feed costs of broilers and layers. The concept of matching production with available feed resources may compromise broiler growth and egg production, but in many countries this may be the most economical choice. Countries in the humid tropics usually have reduced poultry performance. The effects of high temperature and humidity are difficult to overcome. The vexed questions of the escalation in the price of fossil fuel and the outbreak of avian influenza, both seemingly without a solution, are clouds hanging over an otherwise buoyant industry.

Population-based research on diet, obesity and the metabolic syndrome is faced with accumulating evidence of biases that may profoundly affect results. One potential source of bias, which is often neglected in nutritional epidemiology, arises from self-selected study populations. Subjects who agree to participate in surveys may be at less risk of metabolic syndrome than those who refuse. Analogous to observations in adult populations, studies of schoolchildren have also yielded clear evidence of self-selection. Whether such selection patterns influence analytical results depends on how the biases relate to the dependent and independent variables being studied. Systematic dietary reporting error is another source of bias in studies of nutritional risk factors for disease. While obesity-related under-reporting bias is now well documented, less is known about whether specific foods and nutrients are disproportionately affected. However, two studies employing biomarkers for protein have suggested that obese subjects under-reported the proportion of energy from fat plus carbohydrate. This should alert epidemiologists to the possibility that a dual reporting bias may be present in studies of diet and disease: general under-reporting among obese subjects compounded by food-specific errors. In summary, biases due to self-selection and selective dietary under-reporting may produce consequences in epidemiological studies that are both unpredictable and complex. We conclude this review with recent findings involving dietary fat intake and regional adiposity in a population-based study of women. These preliminary results may have etiological relevance to the development of metabolic syndrome, but multiple biases of the type described previously may also be operating.