Incentives and Tranche Retention in Securitisation: A Screening Model Ingo Fender (Bank for International Settlements) and Janet Mitchell (National Bank of Belgium and CEPR)y First draft: November, 2008z This draft: May, 2009 Abstract This paper examines the power of di¤erent contractual mechanisms to in‡uence an originator’schoice of costly e¤ort to screen borrowers when the originator plans to securitise its loans. The analysis focuses on three potential mechanisms: the originator holds a “vertical slice”, or share of the portfolio; the originator holds the equity tranche of a structured …nance transaction; the originator holds the mezzanine tranche, rather than the equity tranche. These mechanisms will result in di¤ering levels of screening, and the di¤erences arise from varying sensitivities to a systematic risk factor. Equity tranche retention is not always the most e¤ective mechanism. The equity tranche can be dominated by either a vertical slice or a mezzanine tranche if the probability of a downturn is likely and if the equity tranche is likely to be depleted in a downturn. In addition, a vertical slice is unlikely to dominate both the equity tranche and the mezzanine tranche, unless the vertical slice is very "thick". Monetary and Economic Department, Bank for International Settlements, Central- bahnplatz 2, 4002 Basel, Switzerland, tel: +41 61 280 8415, email:
[email protected] yFinancial Stability Department, National Bank of Belgium, Boulevard de Berlaimont 14, B-1000 Brussels, Belgium, tel: +32 2 221 3459, email:
[email protected] zThe views expressed in this paper remain those of the authors and do not necessarily re‡ect those of the BIS or the NBB.