The number of births minus the number of deaths (called the "natural increase" by demographers) and net migration are the determinants of growth for a country. One or both of these components can be the driving force of population change, depending on the country and the point in time of interest. In the United States, net immigration is projected to be a predominant factor in our future population growth. At levels presumed by the Census Bureau's middle projection series (which assume net immigration at current levels), immi- grants who come to the United States between 1994 and 2050 and their offspring will be responsi- ble for 60 percent of our total population growth during that period.
Another term for immigrants is "legal permanent residents." These are the people who hold coveted "green cards," which state that they legally reside in the United States. This status confers several privileges that are unavailable to non-citizens who do not hold green cards: those with green cards may permanently live and work anywhere in the country, own property, attend public schools and universities, and join some branches of the armed forces. People who apply to become American citi- zens are typically legal permanent residents. 17
Recent concern about immigration to the United States has been fueled by the number of immigrants, and the perceived and actual influence that immigration exerts on the lives of non-immigrants. Historically, immigrants have borne the brunt of public scorn when economic conditions worsen. However, economic conditions were generally good during the 1990s, yet immigration remained a hotly contested issue in the media and at various levels of government. Part of the reason for this discussion is the differential effect of recent immigration on the resident population. Much of the negative impact is on minorities, according to some research, because the jobs recent immigrants are taking are concentrated at the bottom of the ez, pational ladder, where minorties are dispropore, ately represented.
While the level of immigration is high by recent standards, the proportion of foreign-born persons in the population is not at record levels for the Une states. In 2004, about 12 percent of the populai, was born abroad, more than double the percert, of foreign-born persons in 1970 (about 5 percent but less than the figure at the turn of the century (about 15 percent).
The number of immigrants admitted to the Unites States varied considerably throughout the last.per of the twentieth century, increasing from about 600,000 in the mid-1980s to almost two milionin 1991. After that, the numbers began to decrease. dropping to 647,000 in 1999. One major stalisical reason for the increase was the Immigration Reform and Control Act (IRCA) of 1986, which permitted immigration of former illegal aliens. In 1995, a change in the law permitted such persons to apply directly for naturalization, thus removing them from the count of immigrants. Almost 2.7 immigrants were recorded under IRCA provisions between 1989 and 1994; about 75 percent of those removed "immigrated" in 1989 and 1990. Another reason for the decline was the Immigration Act of 1990, which placed a "flexible" cap on immigration at 700,000 during the 1992-1994 period, and 675,000 thereafter. After 2000, the numbers again began to rise.
In fiscal year 2004, about 946,000 immigrants were admitted to the United States. Of these, only 362,000 (38 percent) were actually new arrivals. The remaining 584,000 were already residing in the U.S. when their status was adjusted. As shown in Table 3-9, the largest single category is "immediate relatives of U.S. citizens," making up almost half the total. In the majority of these cases, the spouse is the U.S. citizen. The next major categories are family-sponsored immigrants (22.7 percent) and employment-based immigrants (164 percent). These two groups are "preference" immigrants, primarily made up of the spouses, children or siblings of U.S. citizens and people eligible for immigration because they have desirable occupations or education. Refugees and asylees are another important immigrant group.
Beginning in the early 1990s, Congress mandated a new "diversity" program, which guaranteed about 55.000 visas to countries that had been "adversely affected" by the 1965 Immigration Act; another 5 percent of immigrants in 2004 were admitted to the United States under this provision. These immigrants were balanced by an estimated 220,000 persons who left the United States, known as the "emigrants." Most immigrants are young, with 40 percent between the ages of 25 and 39 years. The youngest are children adopted by American parents; they accounted for most of the children under 5 years old among the immigrant group.
During the twentieth century, there was a dramatic shift in the countries of origin of immigrants, with fewer arriving from Europe and more originating in Central America and Asia. As was the case throughout the 1990s, Mexico remained the source country for the largest group of immigrants (even excluding IRCA legalizations, which were also pre- dominantly for Mexicans), representing about 18 percent of all immigrants in 2004. The other top five sending countries included the Philippines, Vietnam, China, and India. The largest sending area in Europe encompassed the republics of the former Soviet Union.
Immigrants tend to cluster in a relatively small number of states, with two-thirds of the 2004 group concentrated in six states: California (home to 27 percent of immigrants in 2004), New York (11 percent), Texas (10 percent), Florida (8 percent), New Jersey (5 percent), and Illinois (5 percent).
It is important to note that a large number of persons legally enter the United States each year, but are not immediately enumerated as "immigrants" in official statistics, despite the fact that many end up staying in the United States permanently. Some "classes" of persons can "adjust" to permanent status (and are thus counted as immigrants) after being in the United States for one year (e.g., people granted asylum or refugee status). Such persons are counted as "immigrants" only after they take this adjustment step, even though they may have been in the United States for several years. A major category of non-immigrant entry is the H-1B visas, permitting employers to bring in workers (or to keep workers already in the country) to meet employment needs that cannot be met by American citizens. Most of these jobs are technical in nature and require at least a bachelor's degree. The number of immigrants in the category has declined in recent years, but still amounted to near 400,000 in 2004. However, the largest number of foreigners entering the country each year (more than 30 million) are non-immigrants admitted as temporary visitors, with most coming to the United States on vacation or for pleasure.