# Yield Uncertainty and Strategic Formation of Supply Chain Networks

## TL;DR

This paper examines how supply uncertainty influences the formation and structure of supply chain networks, revealing that retailers tend to under-diversify their supplier links, with different supply improvements affecting welfare differently.

## Contribution

It introduces a model analyzing the strategic formation of supply chain networks under yield uncertainty, highlighting the effects of supply variance and mean on profits and welfare.

## Key findings

- Retailers tend to under-diversify their supplier links.
- Reducing supply variance or increasing mean supply benefits supplier profits.
- Improving expected supply increases overall welfare, while reducing variance can lower consumer surplus.

## Abstract

How does supply uncertainty affect the structure of supply chain networks? To answer this question we consider a setting where retailers and suppliers must establish a costly relationship with each other prior to engaging in trade. Suppliers, with uncertain yield, announce wholesale prices, while retailers must decide which suppliers to link to based on their wholesale prices. Subsequently, retailers compete with each other in Cournot fashion to sell the acquired supply to consumers. We find that in equilibrium retailers concentrate their links among too few suppliers, i.e., there is insufficient diversification of the supply base. We find that either reduction of supply variance or increase of mean supply, increases a supplier's profit. However, these two ways of improving service have qualitatively different effects on welfare: improvement of the expected supply by a supplier makes everyone better off, whereas improvement of supply variance lowers consumer surplus.