Relationships between intermediaries and their customers have become increa
singly important in recent years. This paper argues that the need for costl
y ex ante information acquisition and analysis is a major barrier to the pa
rticipation of investors and firms in sophisticated markets. Long-term rela
tionships between intermediaries and their customers, in which intermediari
es provide implicit insurance to customers, can be an effective substitute
for costly ex ante investigation. Ln this way, intermediaries allow firms a
nd investors to reap the benefits of financial markets. Relationships are e
asiest to sustain when the ongoing benefits to both parties are high. As a
result, competition may lower the benefits that can be obtained from relati
onships.