Since reserves in excess of the required amount did not earn any interest from the Fed before 2008, commercial banks had an incentive to lend to households and businesses until the resulting growth of deposits used up all of those excess reserves.
Hasta 2008, la Reserva Federal no pagaba intereses por el excedente de reservas por encima de esa cantidad, lo que incentivaba a los bancos a otorgar préstamos a particulares y empresas hasta que el incremento de depósitos resultante agotara el excedente.