Diamond's paper analyzes reputation formation in debt markets, focusing on how borrowers' incentives to select risky projects change over time. Borrowers with short credit histories face stronger incentives to choose risky projects due to adverse selection. Over time, as borrowers build a good reputation, their incentives shift toward safer projects. The paper shows that reputation effects are delayed, meaning that borrowers with short track records face more severe incentive problems and may use costly technologies like restrictive covenants or monitoring to mitigate these issues. The model considers three types of borrowers: those with only safe projects, only risky projects, and the ability to choose between the two. Lenders face imperfect information about borrowers' types, leading to initial uniform interest rates. Over time, repayment records provide information that allows lenders to adjust interest rates. The paper demonstrates that a good reputation becomes a valuable asset, and a single default can significantly reduce its value. The model also shows that with a long time horizon, the value of a good reputation increases, making safe projects more attractive. The paper concludes that reputation effects are strongest for borrowers with long track records and that the dynamics of reputation formation have implications for debt markets and general reputation theory.Diamond's paper analyzes reputation formation in debt markets, focusing on how borrowers' incentives to select risky projects change over time. Borrowers with short credit histories face stronger incentives to choose risky projects due to adverse selection. Over time, as borrowers build a good reputation, their incentives shift toward safer projects. The paper shows that reputation effects are delayed, meaning that borrowers with short track records face more severe incentive problems and may use costly technologies like restrictive covenants or monitoring to mitigate these issues. The model considers three types of borrowers: those with only safe projects, only risky projects, and the ability to choose between the two. Lenders face imperfect information about borrowers' types, leading to initial uniform interest rates. Over time, repayment records provide information that allows lenders to adjust interest rates. The paper demonstrates that a good reputation becomes a valuable asset, and a single default can significantly reduce its value. The model also shows that with a long time horizon, the value of a good reputation increases, making safe projects more attractive. The paper concludes that reputation effects are strongest for borrowers with long track records and that the dynamics of reputation formation have implications for debt markets and general reputation theory.