The anti-immigrant organization Federation for American Immigration Reform (FAIR) has released a report which attempts to make the case that undocumented immigrants in the United States impose a massive fiscal burden on native-born Americans. This is a baseless argument that FAIR makes repeatedly, and it rests upon a number of flawed assumptions about the impact that undocumented immigrants and their children have on the U.S. economy.

FAIR begins its fiscal miscalculations by inflating the number of undocumented immigrants living in the United States. Rather than relying upon the standard estimate of roughly 11 million put forth by organizations like the Pew Research Center, FAIR adds another million-and-a-half to the total.

The rationale for doing so is perplexing. According to FAIR, migrants who exist in some sort of quasi-legal immigration status, such as those who have received Temporary Protected Status (TPS), are also considered “undocumented” because their reprieve from deportation is supposed to be temporary. In other words, FAIR believes that migrants should be considered “illegal” even if they have been granted permission by the federal government to remain in the United States because their home countries have suffered some sort of catastrophic misfortune.

Beyond exaggerating the numbers of undocumented immigrants themselves, FAIR also increases its cost estimates through some creative accounting related to the millions of native-born, U.S.-citizen children who have at least one parent who is an undocumented immigrant.

Based on FAIR’s reasoning, these children are just costly extensions of their undocumented parents; consuming schooling and medical care for which their parents don’t pay enough in taxes to cover. In fact, the nativist organization figures that native-born children of undocumented immigrants, as well as the smaller number of children who are undocumented, cost $43.4 billion per year on the taxpayer’s tab for public schooling alone.

This method of accounting ignores one crucial fact about the human life cycle: children are expensive no matter where they were born or what legal status they have. Children use educational and health services that impose costs on the state governments that provide those services, and for which the children themselves pay nothing because they don’t yet have jobs and pay taxes. This applies to the native-born children of native-born Americans just as much as it does to the children of undocumented immigrants.

And yet FAIR views these two groups of children very differently.

When the native-born children of native-born Americans leave school, join the workforce, and become taxpayers, those taxes are counted against the costs they incurred when they were children. But when the native-born children of undocumented immigrants start collecting paychecks, the taxes which are extracted from those paychecks are not counted against the costs which they incurred when they were on the “undocumented” side of the ledger. Rather, the native-born population gets the fiscal credit when these children become taxpayers, while the undocumented population gets blamed for the costs when they are young.

The most accurate way to gauge the economic impact of any person, immigrant or native, is to look at the totality of the contributions they make and services they utilize over the course of their lifetime. Contributions are measured not only in terms of taxes, but also consumer purchasing power and entrepreneurship.

Yet FAIR persists in taking a limited single-year fiscal snapshot of the U.S. population which tells us very little about the actual economic impact that immigrants, be they undocumented or legal, have on the nation as a whole or native-born Americans in particular.