The effect of acute and chronic food shortage on human population equilibrium in a subsistence setting

Abstract

Background: World population is projected to reach 9-11 billion by 2050, raising concerns about food system security and sustainability. Modeling food systems are often a way to understand current and future dynamics. The most common model, first articulated by Malthus (Malthusian), shows population growth as an exponential function and food production as a linear function, concluding that human carrying capacity will be reached leading to mass starvation. Another prominent model was introduced by Boserup (Boserupian), which explains increases in food production as a function of population growth. Methodology: Here, we explore which food systems dynamics exist at equilibrium and after perturbation. The model introduced explores food availability in an isolated village and then in a line of villages. The isolated village model includes three key parameters: maximum calorie production (a), food production resilience (b), and minimum calorie requirement per person (c). The multiple village model adds an additional parameter for trade. Results: Isolated village populations are more resilient to famine than Malthusian theory predicts, suggesting that Malthus' premise may be inaccurate. Predictably, across multiple villages increasing access and production reduce famine. However, under certain conditions large amounts of transport can lead to antagonist relationships leading to rapid changes in population. Conclusion: Food systems under both production and access scenarios proved to be resilient to small perturbations, requiring a large catastrophe to induce mortality; this appeared to discount the Malthusian model. This model can create dynamics where different modes of famine relief apply, but here we see that a balanced approach of both access and production appears to be the most resilient to famine.