Will Households Invest in Safe Sanitation? Results from an Experimental Demand Trial in Nakuru, Kenya

Unsafe sanitation is an increasing public health concern for rapidly expanding cities in low-income countries. Understanding household demand for improved sanitation infrastructure is critical for planning effective sanitation investments. In this study, we compared the stated and revealed willingness to pay (WTP) for high-quality, pour-flush latrines among households in low-income areas in the city of Nakuru, Kenya. We found that stated WTP for high-quality, pour-flush latrines was much lower than market prices: less than 5% of households were willing to pay the full costs, which we estimated between 87,100–82,900 Kenyan Shillings (KES), or 871–829 USD. In addition, we found large discrepancies between stated and revealed WTP. For example, 90% of households stated that they would be willing to pay a discounted amount of 10,000 KES (100 USD) for a high-quality, pour-flush latrine, but only 10% of households redeemed vouchers at this price point (paid via six installment payments). Households reported that financial constraints (i.e., lack of cash, other spending priorities) were the main barriers to voucher redemption, even at highly discounted prices. Our results emphasize the importance of financial interventions that address the sizable gaps between the costs of sanitation products and customer demand among low-income populations.

Do demand characteristics contribute to minimal ingroup preferences?

“Minimal group” paradigms investigate social preferences arising from mere group membership. We asked whether demand characteristics contribute to children’s apparent minimal group bias in a preregistered experiment (N = 160). In a “group” condition, we attempted to replicate findings of bias following assignment to minimal groups. A second closely-matched “no-group” condition retained potential demand characteristics while removing group assignment. Parallel bias in the no-group condition would suggest that demand characteristics contribute to findings of apparent ingroup bias. Three main findings emerged. First, in the group condition, ingroup preference emerged in one of three bias measures only. Second, this preference emerged although participants evaluated ingroup/outgroup photos varying in race/ethnicity between trials. Third, the measure that yielded ingroup preferences in the group condition produced no parallel bias in the no-group condition, consistent with the view that mere membership in a group, not experimental demand, leads to minimal ingroup preferences.

Action Effects on Visual Perception of Distances: A Multilevel Bayesian Meta-Analysis

Previous studies have suggested that action constraints influence visual perception of distances. For instance, the greater the effort to cover a distance, the longer people perceive this distance to be. The present multilevel Bayesian meta-analysis (37 studies with 1,035 total participants) supported the existence of a small action-constraint effect on distance estimation, Hedges’s g = 0.29, 95% credible interval = [0.16, 0.47]. This effect varied slightly according to the action-constraint category (effort, weight, tool use) but not according to participants’ motor intention. Some authors have argued that such effects reflect experimental demand biases rather than genuine perceptual effects. Our meta-analysis did not allow us to dismiss this possibility, but it also did not support it. We provide field-specific conventions for interpreting action-constraint effect sizes and the minimum sample sizes required to detect them with various levels of power. We encourage researchers to help us update this meta-analysis by directly uploading their published or unpublished data to our online repository ( https://osf.io/bc3wn/ ).

Action Effects on Visual Perception of Distances: A Multilevel Bayesian Meta-Analysis

Some studies suggested that action constraints influence visual perception of distances. For instance, the greater the effort to cover a distance, the longer people perceive this distance. The present multilevel Bayesian meta-analysis supports the existence of a small action constraint effect on distance estimation, Hedge’s g = 0.29, 95% CrI [0.16, 0.47] (Nstudies = 37, Nparticipants = 1035). This effect slightly varied according to the action constraint category (i.e., effort, weight, and tool-use) but not according to participants’ motor intention. Some authors argued such effects reflect experimental demand biases rather than genuine perceptual effects. Our meta-analysis did not allow to dismiss this possibility, but it did not support it. We provide field-specific conventions for interpreting action constraint effect sizes and minimum sample size to detect them with various levels of power. We encourage researchers to update this meta-analysis using our online repository (https://osf.io/bc3wn/) to send their published or unpublished data.

The unresponsive avenger: More evidence that disinterested third parties do not punish altruistically

Many social scientists believe humans possess an evolved motivation to punish violations of norms—including norm violations that do not harm them directly. However, most empirical evidence for so-called altruistic punishment comes from experimental economics games that create experimental demand for third-party punishment, raising the possibility that the third-party punishment uncovered in these experiments has been motivated by a desire to appear concerned about social norms rather than by actual concern about upholding them. Here we present the results of five experiments in which we used an aggression paradigm to contrast second-party and third-party punishment with minimal experimental demand. We also summarize the results of these experiments meta-analytically. We found robust evidence that subjects who were insulted by a stranger experienced anger and punished the insulter. To a lesser degree, subjects who witnessed a friend receive an insult also became angry and punished the insulter. In contrast, we found robust evidence that subjects who witnessed a stranger receive an insult did not punish the insulter, although they did experience modest amounts of anger. In only one experiment did we find any punishment on behalf of a stranger, and this result could plausibly be explained by the desire to escape the moral censure of other bystanders. Our results suggest that experimental designs that rely on demand-laden methods to test hypotheses about third-party punishment may have overstated the case for the existence of this trait.

On the Cutting Edge

This epilogue reflects on the ways in which the biomedical odysseys documented in the book open up important questions about the contours of experimentality and the proliferating hopes generated by transnational regenerative medicine. It returns to the metaphor of “cutting edge” in order to illuminate how the experiences of Chinese neurosurgeons and their foreign patients deepen our understanding of the multiple and material ways in which hope transforms technology, travel, and the political economies of health care and medical research in a digitally mediated world. Many of the fetal cell pioneers mentioned in the preceding chapters died during the decade that the author spent researching and writing this book. Their poignant yet grueling encounters with the experimental demand our acknowledgment of the complex ways in which hope endures online and through bodily engagements on the cutting edge of regenerative medicine.

Black Box System Multi-Objective Optimization Based on Design of Experiment

In this paper, a multi-objective parameter optimization model based on experimental design and NN-GA is established. In this method, utilizing experimental design principle to deal with test project and applying NN to map and using Pareto genetic algorithm to optimize, multi-objective parameter optimization is accomplished, in which the high nonlinear mapping ability of neural network model, the global research ability of genetic algorithms and multiform choice about the test points according to experimental demand are utilized synthetically. A Pareto-optimal set can be found in specify region. The method can be applied broadly and it needn’t the concrete mathematic model for different optimizing demand. For virtual devices and products, the virtual experiments can be realized by parameter-driven characteristic.

Application of a Simple Self-Instruction Procedure on Adults' Exercise and Studying: Two Case Reports

In the present research, a simple self-instruction strategy, involving subvocal reading of an index card, was evaluated for two college women concerned about exercise and studying. In both instances experimental demand phase(s) preceded implementation of the treatment to ensure that changes in the dependent measures were attributable to the major intervention. Results indicated that increases in both target behaviors were related functionally to the implementation of self-instruction. Several aspects of self-instructions and the present research were discussed.