Risk-sharing and contagion in networks

  1. Cabrales Goitia, Antonio
  2. Gottardi, Piero
  3. Vega-Redondo, Fernando
Revista:
Documentos de trabajo ( FEDEA )

ISSN: 1696-7496

Any de publicació: 2014

Número: 18

Pàgines: 1-71

Tipus: Document de treball

Altres publicacions en: Documentos de trabajo ( FEDEA )

Resum

We investigate the trade-off, arising in financial networks, between higher risk-sharing and greater exposure to contagion when the connectivity increases. We find that with shock distributions displaying �fat� tails, extreme segmentation into small components is optimal, while minimal segmentation and high density of connections are optimal with distributions exhibiting �thin� tails. For less regular distributions, intermediate degrees of segmentation and sparser connections are optimal. If firms are heterogeneous, optimality requires perfect assortativity in their linkages. In gen- eral, however, a conflict arises between optimality and individual incentives to establish linkages, due to a �size externality� not internalized by firms.