¹Tutorial Fellow in Finance, Merton College and University Lecturer, Said Business School, University of Oxford

^*This article is a modified version of a paper given on 6 September 2001 at a seminar on financial conglomerate regulation at Hoofdorp, The Netherlands, organized by the Council of Financial Supervisors (RFT), the Netherlands Bankers' Association (NVB), and the Dutch Association of Insurers (Verbond van Verzekeraars). I am grateful to Andrew Bain for his comments on the reinsurance market and to an anonymous referee for helpful and constructive criticism.