In the last decade of 20th century, the US was a prosperous country. According to Gordon (2000), economic output remained high, accounting for 4.9% in 1995-1999. Unemployment and inflation were both low. A lot of progressions in computer technology had led to the application were applied widely in management and production; therefore, outcome were higher. A promising future of information technology had attracted the investors. Shares in information technology area became popular and higher led to a higher speculation. Experts called this “Dot-com bubble.” The prosperity of the U.S. ended in 2000, when the “Dot-com bubble” exploded, which together with the sharply increase of petrol price and interest rate had pushed the economy into deep recession from 2001 to 2003. Stock points decreased sharply, especially information technology. NASDAQ index went down for 1,700 points at the end of August 2001, which was 65% lower than its peak in March 2000. Trade deficit and current account deficit were both extremely high, at $350 billion USD and $445 billion USD. Due to the impact of the economic recession, unemployment rate has increased sharply in both native and immigrant population. This has pushed policy makers to a decision to adjust the immigration laws in order to avoid loss in federal budget, and to solve the unemployment problem.