The second traditional strand of arguments in favour of fixed rates sees the exchange rate regime as the anchor for monetary policy. The traditional argument in favour of flexible rates was that it freed a country to apply an independent monetary policy, directed at the needs of its own domestic economy.
The exchange rate could then be a buffer to soften the impact of external shocks such as changes in the terms of trade. And Obstfeld and Rogoff (1995) note that few fixes last longer than five years.