In 2003, there were 4.3 million children of illegal immigrants. By 2008 that number had climbed to 5.5 million, more than the entire population of Colorado. The large number of children of illegal immigrants greatly impacts public schools and education-funding costs.

The Pew study found that in 2008, “Children of unauthorized immigrants are 6.8 percent of students enrolled in kindergarten through grade 12,” an increase from the 5.4 percent in 2003. The proportion was double in California, where 13.5 percent of k-12 students in 2008 were the children of illegal immigrants.

Given these percentages, cost estimates of educating these children are staggering.

The U.S. Census Bureau just released 2008 figures showing the national average total per-pupil funding from all revenue sources was $12,028. Although estimates of the number of school-age children of illegal immigrants don’t separate those attending public vs. private schools, it’s reasonable to assume that nearly all attend public schools since most come from lower-income families. Therefore, if one multiplies $12,028 by the roughly 3.7 million students with illegal-immigrant parents, then one gets a national total funding cost of $44.5 billion.

In California, total funding per pupil from all state, federal and local revenue sources was $11,649. With roughly 923,000 students in the state with illegal-immigrant parents, these students represented a total cost of nearly $10.8 billion out of a total 2008 k-12 education budget of $72 billion. An important caveat is that these totals rely on average per-pupil funding numbers.

The actual cost of schooling these children could be higher because many education dollars are earmarked for special purposes. At the federal level, Title I funds are sent to schools to support disadvantaged children, which benefits many children of illegal immigrants. In California, the state’s Economic Impact Aid program provides tax dollars to fund English-language acquisition, which aids children of illegal immigrants. Capital costs for school construction may have increased at a higher rate because of the influx of children of illegal immigrants.

Although almost three-quarters of the children of illegal immigrants were born in the United States and are therefore citizens, had their parents not entered the U.S. illegally these children likely wouldn’t be in U.S. public schools and wouldn’t require taxpayer funding. Thus, it’s fair to say that their education cost stems from their parents’ illegal entry into this country.

The public-education establishment can’t have it both ways on this issue. The Los Angeles school board, for instance, harshly criticizes Arizona’s immigration enforcement law, but also complains about its own budget shortfalls. The numbers, however, confirm that illegal immigration imposes large costs on the public school system. Policymakers should acknowledge and wrestle with this expensive reality instead of satisfying themselves with cheap rhetoric.

Lance T. Izumi is Koret senior fellow and senior director of education studies at the Pacific Research Institute.