Julian Jamison

University of Exeter | UoE · The Business School

We experimentally evaluate group-based financial education, savings account access, or both for members of Ugandan youth groups. We measure both short- and long-run impacts with one- and five- year endline household surveys. Education, but not account access, increases measured financial knowledge and trust at one-year. At five-years, knowledge eff...

A randomized encouragement design yields null average effects of a credit builder loan (CBL) on consumer credit scores. But machine learning algorithms indicate the nulls are due to stark, offsetting treatment effects depending on baseline installment credit activity. Delinquency on preexisting loan obligations drives the negative effects, suggesti...

This paper examines the links between adverse events, depression, and decision-making in Nigeria. It investigates how events such as conflicts, shocks, and deaths of family members can affect short-term mental health, as well as longer-term decisions on economic activities and human capital investments. First, the findings show that exposure to con...

In this Registered Report, we investigated the impact of a poverty alleviation program on cognitive performance. We analyzed data from a randomized controlled trial conducted on low-income, high-risk individuals in Liberia where a random half of the participants (n=251) received a $200 lump-sum unconditional cash transfer - equivalent approximately...

In most societies, a small number of people commit most of the serious crimes and violence. Short-term studies have shown that cognitive behavioral therapy (CBT) can reduce such antisocial behaviors. There are some signs that these behavior changes may be temporary, however, especially from therapy on its own. This is unsettled, however, for there...

Introduction Reduction of unmet need for contraception is associated with enhanced health outcomes. We conducted a randomised controlled trial in Mozambique analysing the effects of text messages encouraging use of family planning services. Methods This trial was conducted within a sample of women served by the Integrated Family Planning Program i...

Technological advances are enabling roles for machines that present novel ethical challenges. The study of 'AI ethics' has emerged to confront these challenges, and connects perspectives from philosophy, computer science, law, and economics. Less represented in these interdisciplinary efforts is the perspective of cognitive science. We propose a fr...

Classic theories suggest that common pool resources are subject to overexploitation. Community-based resource management approaches may ameliorate tragedy of the commons effects. Here we use a randomized evaluation in Namibia’s communal rangelands to study a comprehensive four-year program to support community-based rangeland and cattle management....

Covid-19 and the measures taken to contain it have led to unprecedented constraints on work and leisure activities, across the world. This paper uses nationally representative surveys to document how people of different ages and incomes have been affected in the early phase of the pandemic. The data was collected in six countries (China, South Kore...

Objective Countries have adopted different approaches, at different times, to reduce the transmission of coronavirus disease 2019 (COVID-19). Cross-country comparison could indicate the relative efficacy of these approaches. We assess various nonpharmaceutical interventions (NPIs), comparing the effects of voluntary behavior change and of changes e...

Given the role of human behavior in the spread of disease, it is vital to understand what drives people to engage in or refrain from health-related behaviors during a pandemic. This paper examines factors associated with the adoption of self-protective health behaviors, such as social distancing and mask wearing, at the start of the Covid-19 pandem...

Classic theories suggest that common pool resources are subject to overexploitation. Community-based resource management approaches may ameliorate “tragedy of the commons” effects. Using a randomized evaluation in Namibia’s communal rangelands, we find that a comprehensive four-year program to support community-based rangeland and cattle management...

In recent years, tax authorities around the world have started using behavioral insights to encourage taxpayers to fulfill their obligations. We review and discuss some of the recent empirical literature on tax compliance. In line with recent trends, we report on a field experiment in collaboration with the tax authority of Latvia (SRS) to encourag...

Background: Countries have adopted different approaches, at different times, to reduce the transmission of coronavirus disease 2019 (COVID-19). Cross-country comparison could indicate the relative efficacy of these approaches. We assess various non-pharmaceutical interventions (NPIs) over time, comparing the effects of self-imposed (i.e. voluntary)...

We perform the first rigorous test of a rules of thumb–based approach to financial education on consumer behavior and outcomes. We test two rules of thumb that are targeted at reducing credit card revolving and deliver them in a randomized fashion via email, online banner, and physical mailer. Using monthly administrative data and pre‐ and postinte...

Bureaucratic performance is a crucial determinant of economic growth, but little real-world evidence exists on how to improve it, especially in resource-constrained settings. We conducted a field experiment of a social recognition intervention to improve record keeping in health facilities in two Nigerian states, replicating the intervention – impl...

This brief provides evidence from World Bank field experiments that consider the social, psychological, and economic factors influencing taxpayer decision-making. Complementary studies from Costa Rica, Guatemala, Poland, Latvia, and Kosovo demonstrate how context-specific, behaviorally informed messaging can offer an immediate, low-cost solution to...

Although inequality in survival is highly correlated with life expectancy, the authors believe that this form of health inequality should be better understood and that inequality in survival could be another useful summary measure of population health. It is also a motivation for assigning priority to the worse-off in priority-setting. Inequality i...

We exploit the principles of choice architecture to evaluate interventions in the market for reloadable prepaid cards. Participants are randomized into three card menu presentation treatments—the market status quo, a regulation-inspired reform, or an enhanced reform designed to minimize attribute overload—and offered choices based on prior structur...

Although the concept of randomized assignment in order to control for extraneous confounding factors reaches back hundreds of years, the first empirical use appears to have been in an 1835 trial of homeopathic medicine. Throughout the 19 th century there was a growing awareness of the need for comparison groups, albeit often without the realization...

The primary focus of this paper is to offer guidance on the analysis of time streams of effects that a project may have so that they can be discounted appropriately. This requires a framework that identifies the common parameters that need to be assessed, whether conducting cost-effectiveness or benefit-cost analysis. The quantification and convers...

Bureaucratic performance is a crucial determinant of economic growth. Little is known about how to improve it in resource-constrained settings. This study describes a field trial of a social recognition intervention to improve record keeping in clinics in two Nigerian states, replicating the intervention-implemented by a single organization on bure...

We conduct laboratory experiments to investigate how private and public information affect the selection of an environmental innovation and the timing of its adoption. The results reveal behavioral patterns underlying the “energy efficiency gap” in which consumers and firms delay adoption of cost-effective energy and environmental innovations. Our...

We show that a number of noncognitive skills and preferences, including patience and identity, are malleable in adults, and that investments in them reduce crime and violence. We recruited criminally engaged men and randomized one-half to eight weeks of cognitive behavioral therapy designed to foster self-regulation, patience, and a noncriminal ide...

Empirical social science relies heavily on self-reported data, but subjects may misreport behaviors, especially sensitive ones such as crime or drug abuse. If a treatment influences survey misreporting, it biases causal estimates. We develop a validation technique that uses intensive qualitative work to assess survey misreporting and pilot it in a...

We show that extremely poor, war-affected women in northern Uganda have high returns to a package of $150 cash, five days of business skills training, and ongoing supervision. Sixteen months after grants, participants doubled their microenterprise ownership and incomes, mainly from petty trading. We also show these ultrapoor have too little social...

By 2009, two decades of war and widespread displacement left the majority of the population of Northern Uganda impoverished. Methods. This study used a cluster-randomized design to test the hypothesis that a poverty alleviation program would improve economic security and reduce symptoms of depression in a sample of mostly young women. Roughly 120...

We conducted experiments during trick-or-treating on Halloween in a predominantly liberal neighborhood in the weeks preceding the 2008 and 2012 presidential elections. We decorated one side of a house porch with McCain material in 2008 (Romney material in 2012) and the other side with Obama material. Children were asked to choose a side, with half...

Intimate partner violence is widespread and represents an obstacle to human freedom and a significant public health concern. Poverty alleviation programs and efforts to economically "empower" women have become popular policy options, but theory and empirical evidence are mixed on the relationship between women's empowerment and the experience of vi...

The paper shows that self-control, time preferences, and values are malleable in adults, and that investments in these skills and preferences reduce crime and violence. The authors recruited criminally-engaged Liberian men and randomized half to eight weeks of group cognitive behavioral therapy, fostering self-regulation, patience, and noncriminal...

We conducted laboratory experiments to investigate how private and public information affect the selection and timing of technology adoption. Our treatments relax the fixed order imposed by the standard herding experiments, but they maintain information parity across subjects and in opportunities for private and social learning. In each round, subj...

We present new results on the relationship between health behaviors and experimental measures of time and risk preferences. In contrast to recent findings in the economics literature, we find no evidence of a link between time preference and self-reported health behaviors and outcomes such as smoking and BMI. We also introduce evidence that interna...

We study the dynamic structure of equilibria in game theory. Allowing players in a game the opportunity to renegotiate, or switch to a feasible and Pareto superior equilibrium, can lead to welfare gains. However, in an extensive-form game this can also make it more difficult to enforce punishment strategies, leading to the question of which equilib...

We present two simple situations in which SPE or NE fail to exist, even though intuition and the motivations for the definitions strongly suggest that they ought to. That is, nonexistence is due merely to technical barriers rather than fundamental barriers inherent in the structure of the situations (as occurs e.g. with auctions). Possibly resoluti...

Do the “ultra-poor” have high returns to capital or are they otherwise constrained? Impoverished Ugandans, mostly women, were experimentally offered individual business training, $150, supervision, and business advising. We evaluated the full package plus the marginal effects of components: supervision (pressure to invest); advice; and stronger soc...

Empirical social science relies heavily on self-reported data, but subjects may misreport behaviors, especially sensitive ones such as crime or drug abuse. If a treatment influences survey responses, it biases causal estimates. We develop a validation technique that uses intensive qualitative work to assess survey misreporting and pilot it in a fie...

We conducted laboratory experiments to investigate how private and public information affect the selection and timing of technology adoption. Our experiments extend the stan-dard herding model to more accurately represent the innovation decision problem. Subjects drew private signals and observed actions of their peer group before making an irrever...

We evaluate the impact of a health information intervention implemented through mobile phones, using a clustered randomized control trial augmented by qualitative interviews. The intervention aimed to improve sexual health knowledge and shift individuals towards safer sexual behavior by providing reliable information about sexual health. The novel...

Players in economic situations often have preferences not only over their own outcome but also over what happens to fellow players, entirely apart from any strategic considerations. While this can be modeled directly by simply writing down final preferences, these are commonly unknown a priori . In many cases it is therefore both helpful and instru...

This volume explores from multiple perspectives the subtle and interesting relationship between the theory of rational choice and Darwinian evolution. In rational choice theory, agents are assumed to make choices that maximize their utility; in evolution, natural selection 'chooses' between phenotypes according to the criterion of fitness maximizat...