Essays on Sustainability in Agriculture and Food Systems

Abstract

Agriculture and food systems face severe challenges from climate change, population growth, and food insecurity. These unprecedented issues leave millions vulnerable to hunger and malnutrition, underscoring the urgent need for a transition toward sustainable agriculture and food systems. The first research stream in this thesis focuses on promoting sustainability in agriculture, particularly through contract farming. In Chapter 2, we model contract farming as a bi-level optimization problem for a farmer and a company. We analytically demonstrate that different contract structures offer varying incentives for farmers to invest in quality-improving efforts, resulting in different levels of quality for agricultural products. Empirical analysis of production-level data supports these model predictions.

The second research stream examines sustainability in food systems, specifically addressing the issue of food waste. In Chapter 3, we explore the impact of online grocery shopping on household food waste. Using large-scale Nielsen Consumer Panel data and instrumental variable analysis, we establish a statistically significant causal relationship, showing that households with higher frequency of online grocery shopping experience lower waste per capita, a proxy of household food waste. These findings emphasize the role of digital platforms in fostering sustainable consumption and call for continued support for online grocery shopping to mitigate consumer-level food waste. In Chapter 4, we turn to retail-level food waste. We design and implement behavioral interventions aimed at reducing food waste in restaurant kitchens in Ghana. As a Sub-Saharan African country, Ghana faces both food waste and food insecurity. Through a six-week field experiment and a difference-in-differences analysis, we demonstrate that interventions focused on public- and private-interest lead to 9% and 19% reductions in food waste in kitchens, respectively. Follow-up surveys and further analyses reveal that this result may be related to the demographic/socioeconomic characteristics of workers (e.g., age and income), their perception of power distance within the management hierarchy, and their satisfaction with restaurant management.