Increasing electricity access remains a challenge, particularly in rural areas of sub-Saharan Africa. This study examines the case of Tanzania, where connection rates remain low even among rural households residing ‘under the grid’, and this despite substantial government subsidies for household connections. Using data from 1,774 rural households living within reach of the electricity grid, we investigate correlates of the low grid electricity uptake. We find that proxies for wealth are positively associated with connection status, while social network variables are less so. Capacity to pay thus appears to remain a major barrier, and in-house wiring costs emerge as a significant expense unaddressed by the existing subsidy scheme, exceeding grid connection costs sevenfold. Similar mechanisms influence the choice between grid electricity and traditional or solar energy sources. These findings inform the ongoing policy debate on subsidy design and the role of alternative energy sources in expanding access.

Public acceptability is crucial for the effectiveness of policy implementation. The carbon trading market is widely adopted by many countries and regions to achieve carbon neutrality and mitigate climate change. Our paper utilizes China's carbon trading market as a quasi-natural experiment, drawing on microdata from the China Residential Energy Consumption Survey to analyze the policy's impact on public acceptance of carbon pricing. We find that the carbon trading market significantly reduces the acceptability of carbon prices among households working in carbon-related industries in the pilot areas. This conclusion is still valid after a series of robustness checks. Regarding the mechanism of influence, the carbon trading market raises households' perceived costs, mainly reflected in the negative impact of rising product prices and increasing living costs. Finally, enhancing public perception of carbon, improving the distribution effect and decreasing the information asymmetry of the policy implementation can improve public acceptability of carbon prices.

Experiments involving games have two dimensions of difficulty for subjects in the laboratory. One is understanding the rules and structure of the game and the other is forming beliefs about the behavior of other players. Typically, these two dimensions cannot be disentangled as belief formation crucially depends on the understanding of the game. We present the one-player guessing game, a variation of the two-player guessing game (Grosskopf and Nagel 2008), which turns an otherwise strategic game into an individual decision-making task. The results show that a majority of subjects fail to understand the structure of the game. Moreover, subjects with a better understanding of the structure of the game form more accurate beliefs of other player’s choices, and also better-respond to these beliefs.

Buying lottery tickets is not a rational investment from a financial point of view. Yet, the majority of people participate at least once a year in a lottery. We conducted a field experiment to increase understanding of lottery participation. Using representative data for the Netherlands, we find that lottery participation increased the happiness of participants before the draw. Winning a small prize had no effect on happiness. Our results indicate that people may not only care about the outcomes of the lottery, but also enjoy the game. Accordingly, we conclude that lottery participation has a utility value in itself and part of the utility of a lottery ticket is consumed before the draw.

Intertemporal choices are affected by both discount rate and utility curvature. We investigate how the two aspects of time preference are affected by the size of the total budget using an intertemporal allocation task. At the aggregate level as well as at the individual level, we find magnitude effects both on the discount rate and on intertemporal substitutability (i.e., utility curvature). Individuals are more patient when dealing with larger budgets and also regard larger budgets to be more fungible. The latter effect suggests that the degree of asset integration is increasing in the stake.

In an artefactual field experiment, we implemented a crowdfunding campaign for an institute’s summer party and compared donation and contribution framings. We found that the use of the word ‘donation’ generated higher revenue than the use of ‘contribution.’ While the individuals receiving the donation framing gave substantially larger amounts, those receiving the contribution framing responded more strongly to reward thresholds and suggestions. An additional survey experiment on MTurk indicated that the term ‘donation’ triggers more positive emotional responses and that emotions are highly correlated with giving. It appears that making a donation is perceived as a more voluntary act and is thus more successful at generating warm glow than making a contribution. We surmise that this extends to other funding mechanisms.

An influential result in the literature on charitable giving is that matching subsidies dominate rebate subsidies in raising funds. We investigate whether this result extends to “unit donation” schemes, a popular alternative form of soliciting donations. There, the donors’ choices are over the number of units of a charitable good to fund at a given unit price, rather than the amount of money to give. Comparing matches and rebates as well as simple discounts on the unit price, we find no evidence of dominance in our online experiment: the three subsidy types are equally effective overall. At a more disaggregated level, rebates lead to a higher likelihood of giving, while matching and discount subsidies lead to larger donations by donors. This suggests that charities using a unit donation scheme enjoy additional degrees of freedom in choosing a subsidy type. Rebates merit additional consideration if the primary goal is to attract donors.

This paper examines the effects of competition in experimental posted-offer markets where sellers can confuse buyers. I report two studies. In one, the sellers offering heterogeneous goods can obfuscate buyers by means of spurious product differentiation. In the other study, sellers offer identical goods and make their prices unnecessarily complex by having multi-part tariffs. I vary the level of competition by having treatments with two and three- sellers in both studies, and having an additional treatment with five-sellers in one study. The results show that average complexity created by a seller is not different for the treatments with two, three and five sellers. In addition, market prices are highest and buyer surplus is lowest when there are two sellers in a market.

We study the impact of endowments and expectations on reference point formation and measure the value of food safety certification in the context of fish trading on real markets in Nigeria. In our field experiment, consumers can trade a known food item for a novel food item that is superior in terms of food safety––or vice versa. Endowments matter for reference point formation, but we also document a reverse endowment effect for a subsample of respondents. The effect of expectations about future ownership is weak and mixed. While expectations seem to affect bidding behavior for subjects “trading up” to obtain the certified food product (a marginally significant effect), it does not affect bids for subjects “trading down” to give up this novel food item. Finally, willingness to pay for safety certified food is large for our respondents—our estimate of the premium is bounded between 37 and 53% of the price of conventional, uncertified food.

We provide a simplified test to determine if choice data from a two-commodity consumption set satisfies the Generalized Axiom of Revealed Preference (GARP), and thus the preference or utility maximization hypothesis. We construct an algorithm for this test and illustrate its application on experimental choice data.

This paper reports the results of an experiment in which subjects had to buy real products in 5 different budget/price situations. Subjects were randomly drawn from the population of a medium-sized French city, and some of their socio-economic characteristics were recorded. We check the consistency of product choices with the Generalized Axiom of Revealed Preferences (GARP), and find that 29% of the subjects are GARP-inconsistent. This inconsistency rate is slightly lower than the ones found in comparable studies. A possible explanation for our lower rate of GARP violations might be that the subjects in our study were confronted with less budget/price situations. In looking for determinants of the GARP violations, we find that gender, the size of the household, the degree of switching between different products, and the times spent on performing experimental tasks have significant impacts on the probability of GARP-inconsistency.

Afriat’s (Int Econ Rev 14(2): 460–472, 1973) critical cost efficiency index is often used to measure the extent to which experimental choice data violate the axioms of revealed preference. Under certain conditions, the index yields a value of one—which typically signifies rational choice—when, in fact, the choice violates the axioms. We term this a cost efficient violation (CEV) of the axioms, clarify the conditions under which it arises, and find that CEVs comprise the majority of violations in three of four studies reviewed. We suggest changes in experiment design to eliminate or reduce the likelihood of CEVs.

It is shown that for two dimensional commodity spaces any homothetic utility function that rationalizes each pair of observations in a set of consumption data also rationalizes the entire set. The result is used to provide a simplified nonparametric test for homotheticity of demand and a measure for homothetic efficiency. The article thus provides a useful tool to screen data for severe violations of homotheticity before estimating parameters of homothetic utility functions. The new test and measure are applied to previously published data.

Has the COVID-19 pandemic affected pro-sociality among individuals? After the onset of the pandemic, many charitable appeals were updated to include a reference to COVID-19. Did donors increase their giving in response to such changes? In order to answer these questions, we conducted a real-donation online experiment with more than 4200 participants from 149 local areas in England and over 21 weeks. First, we varied the fundraising appeal to either include or exclude a reference to COVID-19. We found that including the reference to COVID-19 in the appeal increased donations. Second, in a natural experiment-like approach, we studied how the relative local severity of the pandemic and media coverage about local COVID-19 severity affected giving in our experiment. We found that both higher local severity and more related articles increased giving of participants in the respective areas. This holds for different specifications, including specifications with location fixed effects, time fixed effects, a broad set of individual characteristics to account for a potentially changing composition of the sample over time and to account for health- and work-related experiences with and expectations regarding the pandemic. While negative experiences with COVID-19 correlate negatively with giving, both approaches led us to conclude that the pure effect of increased salience of the pandemic on pro-sociality is positive. Despite the shift in public attention toward the domestic fight against the pandemic and away from developing countries’ challenges, we found that preferences did not shift toward giving more to a national project and less to developing countries.

We elicited incentivized measures of risk and time preferences from a sample of undergraduate students in Athens, Greece, in waves that preceded and overlapped with the COVID-19 pandemic. We exploited the timing of several events that occurred in the course of the pandemic (e.g., first occurrence of cases and deaths, curfew, relaxation of curfew etc.) and estimated structural parameters for various theories of risk and time preferences comparing these with pre-pandemic estimates. We find no effect between the different waves or other key events of the pandemic, despite the fact that we have about 1000 responses across all waves. Overall, our subjects exhibit intertemporal stability of risk and time preferences despite the significant effect of the COVID-19 pandemic on public health and the global economy.

Smith et al. (Econometrica 56(5):1119, 1988) reported large bubbles and crashes in experimental asset markets, a result that has been replicated many times. Here we test whether the occurrence of bubbles depends on the experimental subjects’ cognitive sophistication. In a two-part experiment, we first run a battery of tests to assess the subjects’ cognitive sophistication and classify them into low or high levels. We then invite them separately to two asset market experiments populated only by subjects with either low or high cognitive sophistication. We observe classic bubble and crash patterns in markets populated by subjects with low levels of cognitive sophistication. Yet, no bubbles or crashes are observed with our sophisticated subjects, indicating that cognitive sophistication of the experimental market participants has a strong impact on price efficiency.

We provide a generalized revealed preference test for quasilinear preferences. The test applies to nonlinear budget sets and non-convex preferences as those found in taxation and nonlinear pricing contexts. We study the prevalence of quasilinear preferences in a laboratory real-effort task experiment with nonlinear wages. The experiment demonstrates the empirical relevance of our test. We find support for either convex (non-separable) preferences or quasilinear preferences but weak support for the hypothesis of both quasilinear and convex preferences.

Despite public health efforts, uptake of preventive health technologies remains low in many settings. In this paper, we develop a formal model of prevention and test it through a laboratory experiment. In the model, rational agents decide whether to take up health technologies that reduce, but do not eliminate the risk of adverse health events. As long as agents are sufficiently risk averse and priors are diffuse, we show that initial uptake of effective technologies will be limited. Over time, the model predicts that take-up will decline as users with negative experiences revise their effectiveness priors towards zero. In our laboratory experiments, we find initial uptake rates between 65 and 80% for effective technologies with substantial declines over time, consistent with the model’s predictions. We also find evidence of decision-making not consistent with our model: subjects respond most strongly to the most recent health outcomes, and react to negative health outcomes by increasing their willingness to invest in prevention, even when health risks without prevention are known by all subjects. Our findings suggest that high uptake of preventive technologies should only be expected if the risk of adverse health outcomes without prevention is high, or if preventive technologies are so effective that the risk of adverse outcomes is negligible with prevention.

We present a large scale study where a nationally representative sample of 1000 participants were asked to make real purchases within an online supermarket platform. The study captured the effect of price changes, and of the signposting of such changes, for breakfast cereals and soft drinks. We find that such taxes are an effective means of altering food purchasing, with a 20% rate being sufficient to make a significant impact if (and only if) the tax is signposted. Signposting represents a complementary “nudge” policy that could enhance the impact of the tax, though its effectiveness depends on the product category.

The paper considers what can be inferred about experimental subjects’ time preferences for consumption from responses to laboratory tasks involving tradeoffs between sums of money at different dates, if subjects can reschedule consumption spending relative to income in external capital markets. It distinguishes three approaches identifiable in the literature: the straightforward view; the separation view; and the censored data view. It shows that none of these is fully satisfactory and discusses the resulting implications for intertemporal decision-making experiments.