A study of the economic migration in the US shows a notable reduction in the size of the middle class. Data from 1968 to 1989 obtained from the Survey Research Center's Panel Study of Income Dynamics were analyzed. The study defined middle class in two ways: households with incomes ranging from $18,500 to $55,000 in 1987 dollars, those that are two to six times the poverty line. One of the factors found to have considerable impact on the shrinking of the middle class was the influx of 'economic migrants' into upper and lower classes in the 1980s. However, the factor that contributed the most to the middle class decline was the unequal distribution of men's earnings. The middle class is expected to get even smaller in the 1990s.