青年经济学者论坛
第12期
报告主题
When ROSCA Meets Financial Markets
报告人：柯荣住 助理教授
Massachusetts Institute of Technology 经济学博士
香港中文大学经济学系助理教授
主持人：陈 煜 助理教授
南京大学经济学院经济学系
时 间：2014年4月17日（周四）10:00
地 点：安中楼 307
南京大学经济学院
ABSTRACT: Rotating Savings and Credit Association (Rosca) is an important
informal financial institution in many parts of the world. Existing models
of Roscas assume that their participants do not have alternative financial
devices. However, in reality, evidences show that direct borrowing and
lending may co-exist with Rosca. Then, what is the advantage of Rosca over
direct borrowing and lending (if any)? In this paper, we develop a model
under which risk-averse participants pool their privately known income
shocks to investigate the interesting interactions between Roscas and the
outside financial market. We first consider two extreme cases, without
access to financial market or with a friction less financial market (no
interest rate gap between borrowing and lending). In the first extreme,
we show a bidding Rosca is usually not interim profitable, although it
improves ex ante social welfare under some restrictions. In the second
extreme, we show an impossibility theorem that there is no incentive
compatible and ex ante socially beneficial transfer mechanism (including
bidding Rosca as a special mechanism). However, in the between of these
two extremes, a bidding Rosca is interim profitable, where a friction
(interest rate gap) of credit markets can provide a disciplining mechanism
for Rosca participants to use both financial market and Rosca to smooth
the shock. Finally, to explore the potential of getting around the
impossibility theorem, with some social norm, we show that a Rosca could
still be ex ante beneficial even if the interest rate gap disappears.
KEYWORDS: Roscas, Informal Credit Institutions, Insurance, Private Information