# Parallel Agent-Based Framework for Analyzing Urban Agricultural Supply Chains
## 3 Production and Sales Dynamics in the Supply Chain of Fruits and Vegetables  
We model the production and sales chain of fruits and vegetables among smallholder farmers within the metropolitan city of Santiago and in the sixth region of Chile. We aim to study the interactions between farmers, fairground workers, and consumers, and how these interactions are reflected in trade between these actors.  
In Chile, the Institute for Agricultural Development (INDAP) ([[https://www.indap.go](https://www.indap.go)]([https://www.indap.go](https://www.indap.go)) b.cl/ (accessed on 11 July 2025)) identifies Family Farming (FF) as small-scale producers, typically residing on the land they cultivate, whose primary source of income is their agricultural activity [30]. This type of production accounts for 54% of the vegetables consumed daily at the national level. Farmers have various channels through which to market their products, with open-air markets being the most popular but offering the least added value. Additionally, FFs are characterized by their low rate of technological adoption compared to other larger entities in the industry. These factors, among others, lead to economic inefficiencies for these small-scale farmers. Therefore, it is important to study the decision-making processes and interaction dynamics among the agents in the production and sales chain.  
In this work, we evaluate FFs operating within the metropolitan city of Santiago and in the sixth region of Chile. These farmers make decisions about which products to cultivate and when to sell. These decisions are influenced by factors such as the potential profit for a given product and the risk associated with a product based on various climatic variables, such as the probability of heatwaves, droughs, and frosts. The main distributors of the production obtained by the farmers are the market vendors or fairground workers. These agents act as intermediaries between farmers and consumers. They interact with farmers only in a wholesale market, where the supply and demand for large quantities of products takes place (see Figure 1). Additionally, fairground workers sell the acquired products in various open-air markets. These open-air markets are the primary source from which Chilean families obtain fruits and vegetables, and they constitute the main channel for small farmers to reach consumers. An open-air market is understood as a commerce that operates during fixed hours and in specific locations determined by the local government, where products are traded directly with the public--often informally. There are approximately 1114 open-air markets in Chile, with more than 340,000 registered fairground workers [31]. Open-air markets operate at different times and locations, so the prices at which products are sold are not regulated and depend on the territorial characteristics of the market as well as other factors (e.g., climatic conditions).  
We consider only fruits and vegetables with a cultivation period of less than one year. This is mainly to observe the decision-making process within a shorter time horizon, as the cultivation of, for example, fruit trees is a high-cost strategic decision that takes years to yield results.  
Table 1 shows the fruits and vegetables used in our simulator. We show their sowing months, commercialization periods, and average cultivation time in days. Although certain products are cultivated only during specific months of the year, they are available for sale throughout the year due to product imports from other regions.  
Figure 1: Case Study: Production and distribution chain of vegetables and fruits.