Concerns over global food security are mounting as climate change and geopolitical tensions increase market volatility within food supply chains. In South Korea, these global risks are compounded by significant demographic shifts, characterized by a d...
Concerns over global food security are mounting as climate change and geopolitical tensions increase market volatility within food supply chains. In South Korea, these global risks are compounded by significant demographic shifts, characterized by a declining and aging population. This transformation adds uncertainty to future food demand. At the same time, the country faces a dual challenge of managing a surplus of rice while remaining heavily dependent on imported grains, such as wheat, corn, and soybeans. Given these socio-economic and demographic transformations, along with persistent structural challenges in the food system, it is critical to project structural changes in food demand and to develop strategic frameworks that enhance supply resilience and safeguard food security.
This dissertation presents three empirical studies that examine how demographic change influences food demand and offer insights into developing a secure and reliable grain supply chain. The first study investigates how the age composition of households affects food expenditure by applying the Exact Affine Stone Index (EASI) demand system model to data from the Household Expenditure Survey and Consumer Price Index. Separate models are estimated for single-person and multi-person households to demonstrate heterogeneity in consumption behavior between household types. The effects of prices, income, time trends, and age composition on household food expenditure shares are analyzed across 19 food categories, providing a detailed understanding of consumption patterns across different demographic groups.
The second study forecasts potential structural changes in national food demand through 2050 by applying the EASI model estimates to projected scenarios of demographic trends and household composition. To identify key factors shaping the trajectory of food demand, the study employs Shapley Additive Explanations (SHAP), a machine learning technique grounded in game theory that provides a robust decomposition of each variable’s contribution while accounting for interactions and nonlinear relationships among the factors. This analysis illustrates how demographic and household structural shifts, together with economic variables, may collectively drive the transformation of food demand over time.
Building on the projected changes in food demand, the third study shifts to a supply-side perspective by examining the dynamics of import demand systems for feed grains, namely corn, wheat, and soybean meal. These feed grains are selected as the primary focus of the analysis because they account for approximately 68.2% of South Korea’s total grain imports and play a critical role in enhancing supply chain flexibility and mitigating the impact of external crises, given their relatively high substitution elasticities of demand. Using a comprehensive trade dataset compiled from domestic and international sources, this study applies a dynamic linear logit model to assess substitution elasticities and supply chain vulnerabilities across grain types and countries of origin.
Key findings from the analyses are as follows. The estimation results from the household expenditure functions indicate age as a major determinant in explaining the variation in food consumption patterns. Effects of age on household food expenditure generally exhibit consistent patterns across household types. Younger individuals tend to allocate more of their food budget to snacks, processed foods, and ready-to-eat meals, whereas older individuals allocate a larger share to fresh produce and cooking ingredients. Notably, individuals aged 50 and above exhibited relatively stable consumption patterns regardless of household type or role (i.e., head or member). This suggests that population aging may serve as a key driver of long-term shifts in food demand.
Reflecting structural changes in population and household composition, projected trends in national food expenditure indicate an increased allocation to vegetables, fresh seafood, and grains in 2050. In contrast, the shares for dairy & eggs, confectionery, processed meats, breads & rice cakes, and processed grain products are expected to decline. These shifts are primarily driven by population aging, the rising prevalence of single-person households, overall population decline, and decreasing average household size.
The study also suggests a potential increase in the expenditure share of grains at the national level, despite the declining trend in per capita grain consumption. This seemingly counterintuitive result may reflect the expansion of demographic groups that tend to spend more on grains, as well as shifts in consumption patterns, such as a growing preference for higher-quality grain products and greater variety in food choices.
Households with higher income consistently exhibited greater spending across all food categories, suggesting that quality preferences will play a key role in shaping future food demand in terms of market expenditure. As the share of higher-income households increases, spending on premium and value-added products is likely to significantly influence the structure of national food expenditure. These findings indicate that future shifts in food demand will reflect not only changes in consumption volume but also evolving, demographically driven preferences.
In terms of market size, total national food expenditure is projected to grow at an annual rate ranging from 1.01% to 1.60% through 2050. This projection incorporates the effects of economic stagnation and population decline, suggesting that both the overall expansion of the food industry and the scale of compositional shifts in market expenditure are likely to remain moderate. However, absolute expenditures on fresh produce – especially meats, vegetables, and fruits – are expected to increase more significantly than those in other categories. Remarkably, the estimated impact of age on the expenditure share of meat was relatively modest, suggesting that population aging and overall population decline are unlikely to substantially reduce future meat consumption. In addition, a statistically significant increase in the expenditure share of meat was observed across both household types over time. This trend highlights the growing importance of meat consumption in South Korea’s evolving dietary patterns and its implications for sustained demand for feed grains.
Assuming stable domestic livestock production, rising meat consumption may drive greater demand for imported feed grains, thereby reinforcing reliance on external supply chains. Accordingly, the third study examines the structural characteristics of import demand systems for feed grains to derive policy implications for enhancing supply chain resilience.
The findings reveal that the own-price elasticities of corn and wheat are relatively high and have exhibited an upward trend over the analysis period. During periods of heightened global price volatility, substitution elasticities between the two commodities increased, with fluctuations in corn prices significantly influencing the demand for wheat. This underscores the importance of substitution flexibility between corn and wheat, suggesting that import demand for these grains has become more sensitive to relative price changes.
Corn imports from the major suppliers, including the United States and Argentina, demonstrated relatively high price responsiveness. Imports from Ukraine, despite representing a smaller market share, exhibited greater price elasticity of demand, implying Ukraine’s potential as a strategically important corn supplier. In contrast, wheat imports showed significant reliance on Black Sea countries (Ukraine, Bulgaria, and Romania), while some degree of substitution flexibility was observed across alternative sources.
Soybean meal imports, on the other hand, exhibited declining price elasticity and limited substitutability, with South Korea relying heavily on markets in Brazil and Argentina. This heavy dependence underscores the country’s vulnerability to external supply disruptions and associated risks. Despite the availability of alternative plant-based protein sources, such as dried distillers grains (DDGs) and canola meal, substitution in response to price changes remains limited in practice. Given limitations in domestic production of carbohydrate-based feed grains, mainly due to scarce land and water resources, a more viable strategy may involve developing domestic alternatives and strengthening the supply chain for plant-based protein feed. This approach could contribute to enhancing long-term supply chain resilience and improving grain self-sufficiency.
By integrating food demand projections with a comprehensive analysis of feed grain import dynamics, this dissertation provides strategic insights for addressing emerging challenges within the food system. The findings offer a foundation for developing policies to enhance the resilience, adaptability, and sustainability of South Korea’s food and grain supply chains amid rapid demographic transitions and increasing global volatility.