This paper investigates how the supplier's bargaining power affects trade credit supply. We use a novel firm-level database of Chinese firms with unique information on the amount, terms, and payment history of trade credit extended to customers and detailed information on product market structure and clients-supplier relationships. We document that suppliers with weak bargaining power towards their customers are more likely to extend trade credit, have a larger share of goods sold on credit, and offer a longer payment period before imposing penalties. Important customers extend the payment period beyond what has been offered by their supplier and generate overdue payments. Furthermore, weak bargaining power suppliers are less likely to offer trade credit when credit-constrained by banks. Our findings suggest that suppliers use trade credit as a competitive device in the product market.

The paper presents a new theory of trade credit in which firms buy inputs on credit from suppliers to restore the benefits of secured bank financing impaired by contract incompleteness. In a setting where investment is endogenous and unobservable to financiers, we show that a bank-secured credit contract is time-inconsistent. Upon being granted credit, the entrepreneur has an incentive to alter the original input combination, jeopardizing the bank’s revenues. Anticipating the entrepreneur’s opportunism, the bank offers an unsecured credit contract, reducing the surplus from the venture. One way for the entrepreneur to commit to the contract terms is to purchase inputs on credit from the supplier. The supplier observes the input investment and acts as a guarantor that inputs will be purchased as contracted, thus facilitating access to secured bank financing. The commitment role of trade credit still holds in a multi-period extension that investigates the impact of bank relationship lending on secured debt and trade credit. Our model provides novel testable predictions on optimal financial contracts in both one-period and repeated lending relationships.