Eurozone commercial banks are more vulnerable to shocks because of their failure to open foreign branches, argues a working paper published this month in the latest edition of the Bank of Portugal's Economic studies.

In The euro area financial network and the need for better integration, Nuno Silva uses a "constrained maximum entropy" technique first suggested by Olli Castrén and Michela Rancan to estimate bilateral financial positions taken by actors in seven financial sectors.

Applying this