・"Different Strategies of Crop Diversification Between Poor and Non-Poor Farmers: Concepts and Evidence from Tanzania", Ecological Economics (2025) (with Aya Suzuki) Link
Highlight: It has been widely observed that crop diversification improves farmers’ welfare among the poorest the most. In contrast, poor farmers sometimes struggle to grow multiple crops because they must own enough agricultural resources (e.g., land and seeds). This conflicting nature of crop diversification makes us unsure whether poor farmers are motivated to adopt crop diversification under poverty constraints, and if so, how they are motivated differently from non-poor farmers. To fill in this research gap, this paper illuminates thr potential factors as sources of heterogeneous behaviors on crop diversification between poor and non-poor farmers (subsistence requirement, balanced dietary intakes, and stabilization of market income) and provides their empirical evidence.
→ Presentation Slides used in CSAE conference 2023: Economic Development in Africa
・"Do fertilizer and seed subsidies strengthen farmers' market participation? Evidence from Tanzania's subsidy program", Review of Development Economics (2024) (with Aya Suzuki) Link
(The following working papers are also uploaded in SSRN)
（Papers on secondary cropping）
・"Farmers' Food Security in the Lean Season and Secondary Cropping: Concepts and Evidence from Tanzania" (with Aya Suzuki) pdf (Updated on February 1)
→ Presentation Slides used in CSAE conference 2024: Economic Development in Africa
・Double-Cropping for the Schooling of Children: Evidence from Tanzania (with Aya Suzuki) pdf (Updated on January 19)
→ Presentation Slides used in CSAE conference 2025: Economic Development in Africa
Highlights: To reduce hunger in the lean season, this research sheds light on the short rainy season, a secondary cropping period in East Africa. If farmers cultivate in a secondary cropping period in addition to the main one, they can obtain additional food in a year. One of my papers shows that farmers improve their caloric intakes and dietary diversity by cultivating in the short rainy season. Moreover, this benefit is stronger for resource-poor farmers with small farm size. Another paper shows that welfare improvements are not limited to food security. Additional agricultural income in the short rainy season enables farmers to make their children enroll in and attend schools.
（Papers on the subsistence constraint）
・"Generalizing the Subsistence Constraint for Broad Issues in Development Economics" (with Aya Suzuki) pdf (Updated on January 19)
Highlights: This paper introduces the subsistence constraint into the standard consumer problem. The subsistence constraint is suitable for graphical representation and can easily illustrates behaviors of poor households. For application, the subsistence constraint is used as a conceptual foundation for my empirical papers above. This paper derives microeconomic properties of the subsistence constraint while maintaining its mathematical generality.
→ Presentation Slides used in Japanese Economic Association
（Papers on fishery economics）
・"Restricted Tradability of Harvesting Rights and Unequal Exposure to Binding Resource Limits: Evidence from a Multispecies Fishery in Japan" (with Yutaro Sakai, Keita Abe, & Ryutaro Kamiyama) pdf
Abstract: Rights-based management is becoming central in environmental and resource governance. While the trading of harvesting rights is often restricted by equity concerns, such restrictions may exacerbate inequities when harvesters are heterogeneous. We examine this puzzle in a Japanese purse seine fishery, which introduced individual quotas (IQs) for two species, one of which became quota-constrained. Monetary transactions are not officially allowed in quota transfers, preventing market-based quota reallocation. Using instrumental-variable fixed-effects approaches, we find that higher IQ usage rates for the quota-constrained species reduce catches of the other species, leading to profit losses for fishers operating a single fleet or lacking licenses outside the IQ area. These negative effects are mitigated if fishers can reallocate quotas internally by operating multiple fleets or can access alternative fishing areas. Restricting the tradability of harvesting rights may force harvesters to rely on their operational options, generating unequal abilities to cope with tight quota limits.
Evaluating the performance of the individual quota in Japanese Fishery (with Yutaro Sakai)
Summary:
This research project aims to evaluate the performance of the individual quota (IQ) in the context of Japanese fishery. Under the IQ management, total catch quotas are allocated to fishermen and vessels in advance, which reduces the necessity for fishermen to catch fish earlier than others, alleviates inefficient competition for fishing, and enhances the productivity and fish prices. In cooperation with fishing firms, fishing associations, and the Fishery Agency, we are constructing the unique panel data on daily operation of more than 20 fleets from 2013 and are assessing the performance of the IQ in Japanese fishery.
Impact evaluation of a motivation program for extension officers in Tanzania (with Yuko Nakano)
Summary:
This research project aims to evaluate a policy intervention to enhance the intrinsic motivation of extension officers in Tanzania. In Tanzania, the performance of extension officers is important to improve farmers' adoption rate of agricultural technologies (e.g., fertilizer). In this project, we design a program to enhance the intrinsic motivation of extension officers in cooperation with the Japan International Cooperation Agency (JICA) and evaluate its impact on their job performance.