According to Foreign Exchange Rate Model, The government's policy to stimulate the economy by decreased in Mexico’s domestic interest rate with following the table Peso interest rate from 2008 to 2009 that show interest rate decreased from 3.04 MNX to 2.01 MNX or 51.24%, rates of return on domestic currency deposits to decreased lead to the currency deprecate from 11.13 MNX/USD (2008) to 13.51 MNX/USD (2009) that the changing is the percentage change in large ratio or “Overshooting”.