本文將生產力差距作為訊息不對稱的根源，建立模型並藉以探討競爭性和獨占性借貸市場中的均衡契約以及資源配置的生產決策。研究結果顯示，抵押品在具有訊息不對稱的獨占性市場中是一種有效的分類工具；但在競爭性市場中則未被使用。在獨占性市場中，當低技術企業家的比例足夠低時，最佳的獨占性契約是分離契約；反之，則為混合契約。低技術企業家在分離契約中面臨具約束力的抵押限制，從而導致過度借貸和生產性資源配置不當的問題。 對於競爭性的市場，無論生產力高低，訊息是否完美或具不對稱性，企業家都將獲得相同的貸款契約。

This paper models a productivity gap as the source of informational asymmetry and explores equilibrium contracts as well as production decision of resource allocation in competitive and monopolistic credit markets. Our results show that collateral is an efficient sorting device in a monopolistic market with asymmetric information; whereas it is never used in a competitive market. In a monopolistic market, when the proportion of low-tech entrepreneurs is low enough, the optimal monopolistic contract is a separating contract or, vice versa, it is a pooling contract. Low-tech entrepreneurs face a binding collateral constraint in a separating contract, causing the problems of over-borrowing and productive resource misallocation. For a competitive market, entrepreneurs are granted the same loan contract regardless of their productivity levels and regardless that information is perfect or asymmetric.