Maria Porter

Interests

Research

applied microeconomics, trust, social preferences, risk and time preferences, impact evaluation, intra-household resource allocation

Teaching

microeconomics, econometrics, behavioral and experimental economics, economics of the family, development economics

Courses

Scholarly Contributions

Chapters

• Porter, M. (2010). Marriage and The Elderly in China. In Aging Asia: The Economic and Social Implications of Rapid Demographic Change in China, Japan, and Korea. Washington, DC: Brookings Institution Press.
• King, E., Klasen, S., & Porter, M. (2009). Women and Development. In Global Crises, Global Solutions.

Journals/Publications

• Kramer, B., Porter, M., & Wassie, S. B. (2025).

  Basis risk, social comparison, perceptions of fairness, and demand for insurance: A field experiment in Ethiopia

  . Journal of Risk and Insurance. doi:10.1111/jori.70015
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  Index insurance lowers agricultural risk but covers only covariate risks. Since farmers do not have complete insurance, they may develop mistrust of insurance when experiencing crop losses and not receiving payouts. Although recent innovations in remote sensing enable the provision of more complete insurance including coverage for idiosyncratic risks, such insurance introduces differences in payouts within social networks, which might be considered unfair, introduce jealousy, and depress insurance demand. We conduct a lab-in-the-field experiment with farmers in Ethiopia to examine whether providing complete insurance coverage affects perceived fairness and insurance demand. We also examine effects of informing farmers about neighbors' payout experiences. We find that such social comparison increases perceived fairness of index insurance. Providing complete crop insurance increases perceived fairness of outcomes and willingness to pay for insurance, without introducing jealousy over neighbors receiving different payouts. These results are concentrated among men and those with little insurance knowledge.
• Porter, M., Nuhu, A. S., Nakasone, E., & Maredia, M. K. (2025).

  Trust, risk, and institutions: experimental evidence from a community of firms in Kenya

  . Journal of Economic Psychology, 110(Issue). doi:10.1016/j.joep.2025.102834
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  We study whether personal relationships amongst firms can foster trust as a mechanism to overcome challenging business environments. In partnership with a community of small- and medium-scale enterprises in Kenya, we implemented trust games in a framed field experiment. Our main finding is that outside enforcement of exchanges most effectively increases amounts sent to recipients. A secondary finding is that active members of the business association may be more trusting of fellow members when identities are to be revealed compared to when decisions remain anonymous. Our findings suggest that while association-based networking can perhaps partially offset an adverse business environment, in trust-related decision-making, such informal mechanisms do not fully compensate for lack of outside enforcement that can result from weak institutions.
• Maredia, M. K., Nakasone, E., Porter, M., Nordhagen, S., Caputo, V., Djimeu, E. W., Jones, A. D., Mbuya, M. N., Ortega, D. L., Toure, D., & Tschirley, D. (2024).

  Using novel multi-method evaluation approaches to understand complex food system interventions: Insights from a supply chain intervention intended to improve nutrition

  . Current Developments in Nutrition, 8(6), 103776.
• Maredia, M. K., Nakasone, E., Porter, M., Nordhagen, S., Caputo, V., Djimeu, E. W., Jones, A. D., Mbuya, M. N., Ortega, D. L., Toure, D., & Tschirley, D. (2024). Using Novel Multimethod Evaluation Approaches to Understand Complex Food System Interventions: Insights from a Supply Chain Intervention Intended to Improve Nutrition. Current Developments in Nutrition, 8(Issue 6). doi:10.1016/j.cdnut.2024.103776
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  Background: A “food system” approach to improve diet quality by intervening within areas such as food supply chains is gaining prominence. However, evidence of such interventions’ impact, and understanding of appropriate methods to evaluate them, is lacking. Objectives: We present an impact evaluation of an intervention that aimed to increase consumption of nutritious foods by supporting food-producing firms in Kenya. In doing so, we demonstrate how multiple methods, including those from other disciplines, can be used to evaluate a complex food systems intervention. Methods: Four methods focused on food-producing firms and their management, including a survey of intervention participants (n = 83 individuals), a “laboratory-in-the-field” experiment (n = 83 individuals), baseline/endline data on firm performance (n = 71 firms), and semistructured interviews (n = 19 firms). Three methods focused on consumers in neighborhoods targeted by a supported firm: a randomized field experiment tested effects of making a supported product exhaustively available on consumers’ purchases and consumption (n = 1295 consumers); 3 discrete choice experiments (n = 1295 consumers) tested factors influencing consumers’ willingness to pay for foods with relevant characteristics. Results: Among firms, we saw suggestive evidence of increased networking and business relationships, while laboratory-in-the-field experiments indicated the intervention might foster cooperation among participants. Qualitative interviews suggested that the intervention enabled firms to increase production, improve management, increase revenues, and lower costs. Baseline/endline data confirmed a positive effect only on the launch of new products and hiring workers. In the field experiment, consumption of the supported product increased in areas where it was made available relative to a control group, but this did not increase overall consumption of the food type or dietary diversity. Conclusions: Results showed positive signs of the intervention improving firm-level outcomes but limited impact on consumers’ diet quality. The evaluation also demonstrates how diverse methods can be used to evaluate complex interventions.
• Maredia, M. K., Porter, M., Caputo, V., Nakasone, E., & Ortega, D. (2024).

  Does increasing the availability of a nutritious food produced by a small- and medium-sized enterprise increase its consumption? Evidence from a field experiment in Kenya

  . Applied Economic Perspectives and Policy, 46(2), 414-434.
• Nakasone, E., Porter, M., Jones, A., Maredia, M. K., & Tschirley, D. (2024).

  A mixed methods assessment of technical and financial assistance to small- and medium-sized enterprises in Kenya's food sector.

  . Applied Economic Perspectives and Policy, 46(2), 435-455.
• Nakasone, E., Porter, M., Maredia, M. K., Jones, A., & Tschirley, D. (2024). A mixed methods assessment of technical and financial assistance to small‐ and medium‐sized enterprises in Kenya's food sector. Applied Economic Perspectives and Policy, 46(Issue 2). doi:10.1002/aepp.13426
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  We study the impact of providing consulting services and major capital infusions to small- and medium-sized enterprises (SMEs) in the food sector in Kenya. We exploit a quasi-experimental design that matches treated firms with comparable firms that applied for the same support but were just short of scoring sufficient points to receive this support. Using mixed methods, this quantitative analysis is supplemented by in-depth qualitative interviews, which provide further insights into the workings of the program. The program helped SMEs launch new products and increased numbers of employees. Interviewees described higher sales resulting from the major capital infusions they received.
• Caputo, V., Kaminski, D., & Porter, M. (2023).

  Dairy workers’ preferences for compensatory benefits: A field choice experiment with U.S. immigrants and students 

  . Journal of the Agricultural and Applied Economics Association, 2(2), 198-214.
• Farris, J., Porter, M., Jin, S., & Maredia, M. K. (2023).

  Growing Pains: Timing of In Utero Rainfall Shocks and Child Growth in Rural Rwanda

  . Economic Development and Cultural Change, 71(2), 793-818. doi:10.1086/714886
• Maredia, M., Porter, M., Nakasone, E., Orega, D. L., & Caputo, V. (2023). Does increasing the availability of a nutritious food produced by a small- and medium-sized enterprise increase its consumption? Evidence from a field experiment in Kenya. Applied Economic Perspectives and Policy, 1-23.
• Kassas, B., Palma, M. A., & Porter, M. (2022). Happy to take some risk: Estimating the effect of induced emotions on risk preferences. Journal of Economic Psychology, 91, 102527.
• Wang, Y., Porter, M., & Jin, S. (2020). The impact of health insurance on healthcare service use and costs: evidence from rural China. China Agricultural Economic Review, 13(2), 418-435. doi:10.1108/caer-06-2020-0148
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  PurposeThe purpose of this paper is to study the effects of introducing a health insurance program in rural China between 2004 and 2006, the New Cooperative Medical Scheme (NCMS).Design/methodology/approachThe authors apply difference in difference and propensity score matching methods (PSM-DID) to a widely used panel dataset, the China Health and Nutrition Survey (CHNS). Findings are robust across several treatment and comparison groups used in previous NCMS studies.FindingsHouseholds who participated in NCMS increased the use of preventive services and western medicine, while lowering the use of traditional Chinese medicine. NCMS also reduced hospital use, out of pocket payments, travel time to healthcare facilities and waiting time to see doctors. The authors estimate that reductions in travel and waiting time saved roughly 52m U.S. dollars in 2006.Research limitations/implicationsPreviously divergent findings on health insurance effects may be due to researchers studying health insurance across different healthcare delivery systems. In addition, in estimating how health insurance access affects healthcare costs, the authors should consider economic costs related to the time needed to access health services.Originality/valueThe authors study how health insurance access affects patients' choice of providers and economic costs to accessing health care services, outcomes that have not received much attention previously. The authors depart from previous NCMS studies by comparing several different approaches to identifying treatment and control groups when applying PSM-DID.
• Porter, M. (2017). Spousal Bargaining Over Care for Elderly Parents in China: Imbalances in Sex Ratios Influence the Allocation of Support.. The journal of development studies, 53(4), 514-529. doi:10.1080/00220388.2016.1156093
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  Using a unique Chinese survey of parents and adult children, this paper examines how married children negotiate with their spouses for time devoted to caring for their own parents. Applying a collective bargaining framework, I show that the sex ratio at marriage shifts household bargaining in favour of the husband's parents when women are less scarce, or against his parents when women are scarcer. Such changing dynamics in the family may potentially reverse the current preference for sons in China, implying that those with sons, rather than daughters, may be increasingly in need of state support.
• Porter, M. (2016). Effects of microcredit and other loans on female empowerment in Bangladesh: the borrower's gender influences intra-household resource allocation. Agricultural Economics, 47(2), 235--245.
• Porter, M. (2016). How do sex ratios in China influence marriage decisions and intra-household resource allocation?. Review of Economics of the Household, 14(2), 337--371.
• Porter, M., & Adams, A. (2016). FOR LOVE OR REWARD? CHARACTERISING PREFERENCES FOR GIVING TO PARENTS IN AN EXPERIMENTAL SETTING.. Economic journal (London, England), 126(598), 2424-2445. doi:10.1111/ecoj.12248
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  Understanding the motivations behind intergenerational transfers is an important and active research area in economics. The existence and responsiveness of familial transfers have consequences for the design of intra and intergenerational redistributive programmes, particularly as such programmes may crowd out private transfers amongst altruistic family members. Yet, despite theoretical and empirical advances in this area, significant gaps in our knowledge remain. In this article, we advance the current literature by shedding light on both the motivation for providing intergenerational transfers, and on the nature of preferences for such giving behaviour, by using experimental techniques and revealed preference methods.
• Porter, M. (2010). Health, Longevity, and the Role of the Family in China. Journal of Population Ageing, 3(3-4), 103--109.