# Manufacturer Channel Encroachment and Evolution in E-Platform Supply Chain: An Agent-Based Model
## 5 Discussion
### Extended Model  
In the basic model, we assume that there are two kinds of similar products of different quality in the supply chain. However, in real life, there is diversity in products, both vertical differences, such as quality differences, and horizontal differences, such as style and colour differences. This part discusses the extended model construction and analysis ideas under product diversity, and looks forward to the direction of future research.  
In the extended model, a manufacturer simultaneously sells the same type of product but of different quality, and there is a difference in style from the products sold by other manufacturers. Heterogeneous consumers choose one manufacturer in one channel to purchase products. In the study of multi-product problems, scholars usually use Salop circle model, which uses a circle to represent the virtual distance between consumers and sellers and to describe the horizontal differences between products [51; 52; 53]. Since consumers purchase two kinds of products, it is assumed that there are two circles, representing high-quality product collections and low-quality product collections, respectively. In a circle, the different products sold by manufacturers are evenly distributed on the circumference. Consumers are randomly distributed on the circumference.  
The manufacturer's behaviour is consistent with the basic model, and also makes price decisions and optimizations for products in different channels and formulates channel strategies. For consumers, their position on the circumference has an impact on their utility. When a consumer chooses to purchase products from manufacturers with a distance \(d\) from him, he needs to bear the cost \(f(d)\)[54]. Since different products are distributed in different locations, the cost to consumers is also different. Thus, the utility of the consumer can be expressed as: \(U_{j}^{t}=U_{jH}^{t}+U_{jL}^{t}=\left(V_{H}^{t}-P_{H}^{t}-f\big{(}d_{jH}\big{)} \right)+\left(V_{L}^{t}-P_{L}^{t}-f\big{(}d_{jL}\big{)}\right)\). \(V_{H}^{t}\), \(V_{L}^{t}\) are the consumer's valuations of high-quality products and low-quality products, respectively. \(P_{H}^{t},P_{L}^{t}\) are the prices. Consumers choose to buy products from one manufacturer by comparing different manufacturers in different channels to maximize utility.  
Similarly, the multi-period simulation and data recording of the model can extend the conclusions in the basic model to the multi-product scenario, so as to analyse how the e-commerce supply chain will evolve under the influence of different factors at this time. The number of product categories in the market can be changed by changing the number of manufacturers, to analyse the impact of the number of categories on the evolution of the supply chain. In the extended model, the random distribution of consumers can be either concentrated or dispersed--how will this affect the implementation of the manufacturer's dual-channel strategy? How will the distance cost of consumers affect the model? These problems are waiting to be solved in the multi-product model.