Chapter 1 theoretically shows why lenders ration loan size and loan applicants to screen borrowers' riskiness in a competitive spot loan market with imperfect information. Chapter 2 theoretically examines how lenders can reduce costs to screen borrowers' riskiness by a commitment to grant a loan in the future and including a material adverse change (MAC) clause while a spot loan market co-exists. Chapter 3 empirically tests how borrowers' impatience can be used to screen their private information about default risk.