Numbers and Geographic Distribution

A Rapidly Growing Population. Partly as a result of reforms in immigration law in the 1960s, the level of immigration has increased dramatically over the last three decades. This influx has caused an enormous growth in the nation’s immigrant population, from less than 10 million in 1970 to more than 28 million today. Mexican immigrants have accounted for a large and growing share of this growth. Figure 2 reports the number of Mexican immigrants living in the country over the last 30 years. Since 1970, the size of the Mexican immigrant population has increased 10-fold, from less than 800,000 to nearly eight million today. The number of immigrants from countries other than Mexico has increased less dramatically, from 8.9 million in 1970 to 20.5 million in 2000. Overall, the growth in the Mexican immigrant population accounts for 37.8 percent of the total increase in the number of immigrants living in the United States.

Lower Fertility in Mexico Is Not Leading to a Reduction in Immigration.

Figure 2 also shows the total fertility rate of women living in Mexico. It is often suggested that declines in fertility in Mexico will lead to a reduction in out-migration from that country since there will be fewer young workers who will need to migrate north in search of employment. However, the historical data do not provide any support for this conclusion. While Mexican fertility has fallen dramatically over the last three decades, the number of Mexicans coming to the United States has increased dramatically. There can be no question that migration is a complex progress affected by many factors, and fertility may be one of those factors. However, the historical data indicate that a reduction in Mexican fertility by itself will not necessarily lead to a reduction in immigration. Without a change in U.S. immigration policy, it seems almost certain that immigration from Mexico will remain at very high levels for several decades even if fertility in that country continues to fall.

Mexican Immigration Is a Recent Phenomenon.
In addition to asking about country of birth, the Current Population Survey also asks individuals what year they came to the United States. The data show that a large percentage of Mexican immigrants are new arrivals. In 2000, almost three-fourths (73.6 percent) of Mexicans living in the United States had arrived in the country in just the last 20 years. In contrast, of non-Mexican immigrants only 47.4 percent have lived in the country for 20 years or less. Along with Figure 2, the year of arrival data indicate that large-scale immigration from Mexico is a relatively new phenomenon for the United States.

Mexicans Are a Growing Share of the Foreign-Born.
Because the Mexican immigrant population has grown more rapidly than the number of immigrants from other countries, Mexican immigrants represent a growing share of the nation’s total foreign-born population. Figure 3 shows Mexican immigrants as a share of all immigrants. In 1970, Mexicans represented less than 8 percent of the foreign-born, but in 2000 they accounted for almost 28 percent. Both in absolute numbers and relative to other immigrants, the Mexican immigrant population has increased enormously over the last three decades.

A Highly Concentrated Population.
In addition to the rapid increase in numbers, Mexican immigration is highly concentrated. Figure 4 shows the share of Mexican and non-Mexican immigrants living throughout the regions of the United States. With almost 63 percent of Mexican immigrants, the West is the most affected region. In contrast, the figure shows that immigrants from countries other than Mexico are nowhere near as concentrated. The West, South, and Northeast each account for roughly 30 percent of the nation’s non-Mexican immigrant population. The Mexican population is even more concentrated than Figure 3 suggests. Almost half — 48.2 percent, or 3.8 million — of all Mexican immigrants live in just one state: California. Of non-Mexican immigrants, 24.3 percent live in California. In addition, Texas, which is included in the figures for the South, accounts for another 18.5 percent or 1.5 million of all Mexican immigrants living in the United States. Together, Texas, California, and the other two border states of Arizona and New Mexico account for 72.7 percent of Mexicans who have settled in the United States (see Table 1).