Energy efficiency is a key component of climate policy. The rebound effect, namely the increases in demand in response to efficiency-induced price reductions, potentially nullifies some of the energy savings from energy-efficiency improvements. This paper examines macro rebound effects following the introduction of energy-efficient biomass cookstoves (EEBCs) in rural Sub-Saharan Africa. It presents a model of biomass supply and demand, and empirically evaluates a government pilot project in Rwanda that randomly subsidized EEBCs at the village level, leading to exogenous variation in adoption rates. The paper explores consumption spillovers to nonadopters through price reactions on local village markets, referred to as the “local macro rebound effect.” The theoretical model and empirical results show that equilibrium response effects can take different forms, depending on the local context. The paper identifies conditions that determine the shape and size of such effects.

Low productivity in agriculture is a major cause of poverty and food insecurity in Africa. One explanation for low productivity is the widespread presence of low-quality inputs on local markets (“lemon technologies”), which causes uncertainty among farmers and erodes incentives for adoption. We report the results from a field experiment in Tanzania to study the impact of improved maize seeds in a context where we exogenously vary seed quality and uncertainty about seed type. The analysis is at the level of experimental plots owned and managed by farmers (not the entire farm). While improved seed positively affects harvests and reduces the probability of crop failure among fully-informed farmers, these benefits are attenuated significantly when farmers are uncertain about the seed type they receive. The main channel linking uncertainty to lower harvest levels is the re-allocation of labor—a complementary input. The presence of lemon inputs on the market for modern inputs impedes learning about the profitability of these inputs and increases the yield gap by slowing down adoption in subsequent periods.

Malaria is a major public health problem in Africa. Traditional methods of controlling malaria no longer provide adequate protection against transmission, and future approaches likely require a combination of technical solutions and behavioral change. We use a cluster randomized controlled trial to study the impacts of an intervention that combines house screening with a behavioral intervention based on health messaging. While house screening provides modest positive benefits, these benefits can be leveraged if it is combined with health messaging. We provide tentative evidence that the impact of messaging varies with the design of the choice architecture: loss-framed health messages seem to do better than gain-based messages--our data suggest they may have larger and more durable effects on behavior and health outcomes.

We compare the impact of two extension modalities on knowledge accumulation and willingness to pay for a weather index insurance product among smallholder farmers in Kenya. One approach to extension is based on experiential learning and involves participation in an incentivized framed experiment (or game). The other is based on conventional "narrative-based" learning. While both modalities increase farmer knowledge, incentivized gamification causes more learning. We also find that experiential learning affects follow-up demand for the insurance product, which is not true for narrative-based learning. Interestingly, demand for insurance shifts inward after playing the insurance game. This reduction in demand is mainly caused by increased knowledge about the insurance product, but we also present suggestive evidence that experiencing basis risk during the game was more salient than theory-based learning about basis risk. Game-based learning is an effective approach to promote knowledge accumulation and may accentuate or attenuate adoption of innovations by updating ex-ante, possibly biased, expectations.

The development of high-yielding, resilient cultivars is the primary goal of many crop breeding programmes, but the uptake of these new cultivars is persistently low in low-income countries. We discuss constraints related to the adoption of crop cultivars and stress the importance of participatory approaches in building trust and promoting the adoption of new technologies.

The presence of monitoring institutions affects quality and effort of leaders. We investigate the effect of intensified monitoring on the ability and effort of leaders for a sample of forest user groups in Ethiopia, and find experimental and non-experimental evidence of an important trade-off: monitoring increases leaders' effort but lowers their quality in terms of education and experience. This effort-ability trade-off only occurs in the presence of alternative income opportunities (affecting the opportunity cost of time) and only among a subsample of leaders with low prosocial motivation. For our context, we document that the net effect of monitoring on economic outcomes is positive.

We analyze how market power by traders on local agricultural spot markets affects investment in crop quality by smallholders in a context with "imperfect institutions"—without third-party contract enforcement and with incomplete input markets. Farmers and traders can engage in relational contracting where the promise of future rents supports current cooperation. We analyze informal contracting under the shadow of side selling by the farmer and ask how changes in the competitiveness of local markets affect flows of inputs in relational contracts. When local markets become more competitive, fewer farmers are included in relational contracting with traders, and farmers who remain in such relationships receive less support from traders. We document empirical evidence from local wheat markets in Ethiopia that is consistent with the theory.

We study how temporary provision of an agricultural innovation at zero cost affects long-run demand for that innovation. Our experimental design enables us to distinguish between an "anchoring effect" of subsidies and a "learning effect." We document large and persistent anchoring and learning effects. For the innovation that we consider, an integrated pest management (IPM) package for Ethiopian smallholder farmers, the learning effect dominates the anchoring effect, so temporary subsidized provision promotes long-run technology diffusion.

Evidence of the impact of community-based forest management (CBFM) on conservation outcomes is mixed. Local governance is a key moderating factor, but what constitutes good governance is still up for debate. Desirable institutional features typically arise endogenously, which complicates the analysis of causality. We use an experimental design to analyze the impact on environmental outcomes of adding an externally implemented monitoring regime to an existing CBFM initiative in Ethiopia. We distinguish between bottom-up and top-down monitoring to improve the accountability of local leaders. We find that enhanced bottom-up monitoring by community members does not affect forest outcomes, but top-down monitoring promotes forest conservation. We also identify a mechanism linking top-down monitoring to conservation: leaders work harder to protect the forest, which “crowds in” effort by community members. Our results are not about reducing the role of communities in forest management, they are a plea for oversight by the relevant authority to help communities overcome local power asymmetries.

How does agricultural insurance affect the modernization of farming in low income countries? We focus on institutional contexts without formal contract enforcement, where smallholders cannot access modern inputs via markets. Instead, farmers can engage in relational contracting with traders to sell their crop and gain access to inputs (as an advance in-kind payment). Although conventional theory assumes that insurance "crowds in" modern inputs by attenuating investment risk, we demonstrate that insurance reduces the number of farmers receiving modern inputs from traders. Insurance also reduces the quantity of inputs that traders provide to farmers who remain in a relationship. Insurance may impede the uptake of modern inputs when institutions are imperfect.

We use a randomised field experiment to study short-term and medium-term impacts of a training intervention that aims to increase employability of Rwandan (underemployed) youths. The training includes networking and mentorship as well as modules on developing entrepreneurship, technical skills and soft social skills. We evaluate intended outcomes of the training on attitudes towards work, employability and labour market outcomes. We also consider unintended social impacts of the training. The outcomes of the intervention are modest. While on the short term the training positively impacted ‘work readiness’ and networking, we do not document significant effects on employment status or income. In the medium term, we do not find any significant effect. Non-compliance and attrition reduced statistical power of our analysis.

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.

Information does not flow freely through social networks. We use an experiment to study knowledge diffusion about an innovation (integrated pest management, IPM) in farmer groups in Ethiopia. Group leaders are incentivized to share knowledge with members through the conditional provision of material or social prestige rewards. We combine incentives with loss-framed messaging to leverage loss aversion. Incentives increase diffusion effort, and combining incentives with loss-framed messaging increases effort further. However, the treatments failed to induce follower farmers to experiment with IPM. We also document that reclaiming material rewards is difficult after a long delay, attenuating the effectiveness of the loss frame.

Malaria imposes an economic burden for human populations in many African countries, and this burden may be reduced through house screening initiatives. We use a randomized controlled trial to measure the economic impacts of house screening against malaria infection. We use a sample of 800 households from 89 villages in rural and peri-urban Zambia to collect baseline data in August 2019 and endline data in August 2020. The main outcome variables are (self-reported) malaria prevalence rates, labor supply, and income, and consider individual and household-level outcomes. House screening reduces malaria prevalence, the number of sick days due to malaria, and the number of malaria episodes. Impacts on adults are more pronounced than on children. In terms of economic impacts, house screening increases labor supply and (household) income. We find particularly large effects on labor supply for women household members. A cost-benefit analysis, based on estimated benefits and measured costs, suggests that the private benefits of house screening exceed the costs. While not all houses are suitable for house screening, we conclude that screening is a promising and cost-effective approach to reduce malaria infections.

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers. Examining drivers of the latitudinal biodiversity gradient in a global database of local tree species richness, the authors show that co-limitation by multiple environmental and anthropogenic factors causes steeper increases in richness with latitude in tropical versus temperate and boreal zones.

Agricultural (index) insurance for smallholders in developing countries has gained traction in academic and policy circles. The expectation is that the uptake of insurance will protect smallholders from production shocks and incentivize them to modernize production. We develop a simple theoretical model to demonstrate that the welfare effects of insurance are fundamentally ambiguous-even in the absence of transaction costs or basis risk. The second-best nature of the institutional context within which smallholders operate implies that the uptake of insurance may accentuate pre-existing inefficiencies. This idea is worked out in detail for the case of livestock herding on common grazing lands. Our theoretical model predicts that insurance invites overstocking of communal lands, and lowers the profitability of herding when common pastures are degraded.