Bird, Samuel S., Michael R. Carter, Travis J. Lybbert, Mary Mathenge, Tim Njagi, and Emilia Tjernström. "Filling a niche? The maize productivity impacts of adaptive breeding by a local seed company in Kenya." Journal of Development Economics 157, 2022. [Published journal article] [Accepted manuscript] [ATAI Summary] [AMA Policy Brief]
This paper studies whether the absence of locally adapted seed varieties constrains the productivity and incomes of farm households residing in small, agro-ecological niches. We empirically examine the disruption of the maize seed market in Western Kenya that took place when public sector foundation breeding and social impact investment capital came together and allowed a local seed company to expand and target a niche area with adaptively-bred maize varieties. The three-year randomized controlled trial reveals that these seed varieties increased farmer yields and revenues, both for better-resourced farmers (who used non-adapted hybrids and fertilizer prior to the intervention) as well as less well-resourced farmers (who did not). This theoretical and empirical evidence suggests news ways for thinking about seed systems in areas typified by high levels of agro-ecological heterogeneity.
* Best Publication of 2022 Award -- Agricultural & Applied Economics Association Africa Section
Bird, Samuel S. and Aleksandr Michuda. "Ethnic diversity and voting behavior at scale: Evidence from Uganda." World Development, forthcoming. [Full paper available on request]
This study constructs a novel dataset on the ethnicity of individuals in an ethnically diverse country in sub-Saharan Africa. We measure ethnicity using a machine-learning algorithm that exploits variation in surnames across ethno-linguistic groups. We apply this approach to voter registration data from Uganda's 2016 general election. The resulting data capture local variation in ethnicity over a wide geographic scale. We pair these data with election outcomes from polling stations throughout Uganda to estimate the relationship between ethnicity and voting behavior. Our regression analyses both control for location and include interactions between ethnic groups within the same polling station. Local variation in ethnicity is associated with voting behavior at the level of the polling station, and these relationships vary with the presence of other ethnic groups at the polling station. The results suggest the importance of studying ethnic voting using local variation in ethnicity at scale.
Agricultural mechanization and gendered structural transformation in India (with Kajal Gulati, Koustuv Saha), August 2025.
Adoption of modern methods of mechanized tilling in India caused a dearth in women's job opportunities in agriculture. While men were reabsorbed into the restructured agricultural sector or into non-agricultural jobs, women's labor force participation in rural India fell. Using the staggered roll out of the national rural employment guarantee scheme (NREGS) we examine if the creation of jobs under the scheme mitigated the fall in women's labor force outcomes due to the adoption of labor saving technology in agriculture. Instrumenting mechanization by the exogenous variation in the share of in the share of loamy soil and clayey soil across districts, we show that while the NREGS did slow down the fall in women's weekly work days it was not sufficient to offset the effect of mechanization. At the extensive margin, NREGS was not successful at reducing the number of women exiting the labor force, though it had a positive effect on the intensive margin, number of days of work in a week. We surmise that if the NREGS was targeted to districts especially affected by gendered structural transformation, it could be more effective in stemming the fall in female labor outcomes in rural India.
Aspirations, beliefs, and behavior: Economic outcomes from a randomized religious intervention (with Susan Kilonzo, Vivek Moorthy, David Murphy), August 2025. [AEA RCT Registry]
We study how religion influences economic behavior using a randomized control trial in Kisumu, Kenya. Participants attended workshops hosted by either Pentecostal or mainline Christian churches, followed by surveys and incentive-compatible choice experiments to measure altruism and investment behavior. Pooling both treatments, we find that attending the services led to decreased self-reported self control and grit while reducing contributions to a communal entrepreneurship fund by 16.3% relative to the control. Examining denominational differences, we find evidence that a shifting landscape toward Pentecostalism matters: Pentecostal messaging appears to have decreased the amount of financial transfers received and given by the respondent and further increased interest bearing savings among men and intrinsic religiosity among women. These findings provide causal evidence that Christian religious participation promotes individualism at the expense of collectivism, while demonstrating that Sub-Saharan Africa's changing denominational composition may further amplify such effects with economically meaningful implications for investment behavior.
Using farmer groups to share information (with Michael Carter, Laura Meinzen-Dick), November 2024. [Full paper]
We study material and informational constraints to adoption of a subsidy for agricultural inputs in Uganda. We randomly assign farmer organizations to be offered no subsidy, a status quo subsidy, or a higher initial subsidy. Material constraints to adoption bind for some farmers: the status quo subsidy has no significant effect on adoption, but the high subsidy substantially increases adoption. Informational constraints to adoption also bind for some farmers: group leaders are more likely to adopt than general members, and member adoption increases with leader experience with improved agricultural inputs as well as social similarity to the member.
Technology adoption and market participation in smallholder agriculture, September 2024. [Full paper]
This paper studies whether the adoption of a technology that increases the production of a staple crop differs between households who are buyers, sellers, or self-sufficient with respect to the staple crop. I develop a theoretical model that shows that if buying or selling staples incurs large fixed costs, technology adoption varies with market participation; if fixed costs are small, however, technology adoption does not vary with market participation. Whether technology adoption varies by market participation has implications for how to target interventions promoting technology adoption such as input subsidy programs. I estimate how adoption varies with market participation using data from a randomized controlled trial of high-yielding varieties of maize developed for western Kenya. Treatment effects across market participation groups are neither large nor statistically significant. These results suggest that transaction costs in output markets are not large enough to shape the pattern of adoption of a production technology.
Gender and market participation: Evidence from Ugandan agriculture (with Sneha Verma, Luther College '22), June 2021.
This paper estimates how sales of staple food crops differ between female and male members of agricultural households. We estimate this effect by controlling for fixed effects for household and crop using panel data from the Government of Uganda for the Living Standards Measurement Survey – Integrated Survey of Agriculture from 2009- 2015. Sales are greatest for harvests controlled by a single male, followed by harvests controlled by a female and male and harvests controlled by a single female. Some differences between genders are due to the condition in which the crop is harvested. We also estimate that restricting survey respondents to report a single decision-maker creates large measurement error in decision-maker gender as well as some bias when estimating the relationship between market participation and gender. Our results highlight differences in output market participation by gender as well as the importance of accounting for all household members involved in decision-making processes.
Program targeting and design: Input subsidies in smallholder agriculture, November 2019.
Many governments in sub-Saharan Africa subsidize the use of agricultural inputs by smallholder farmers in order to increase food production and food security. These subsidy programs have been studied empirically in country-specific contexts, yet we lack a theoretical understanding of how program impacts vary with program targeting and subsidy level. I use numerical simulation to study a policymaker’s optimal targeting and design of a subsidy program given farmers’ best responses of input use under different subsidy levels. I find that the policymaker’s optimal targeting and subsidy level critically depend on the distribution of land and financial wealth across households.
Agricultural technology adoption, market participation, and price risk in Kenya, December 2017.