The Federal Deposit Insurance Corp., the Federal Reserve and the Office of the Comptroller of the Currency have proposed tougher but simpler capital requirements for banks. The rules would effectively force the biggest banks to hold capital equal to between 5% and 6% of assets. "This will increase the overall financial stability of the system," FDIC Vice Chairman Thomas Hoenig said. "This is an advantage to the banks over the long run, and to the economy. I am confident of that."