Businesses and immigration groups say they have already tallied some of the effects of the law.
Advocates for immigrants contend that, at a minimum, hundreds of people unauthorized to work have left the state or been fired. Some school districts have at least partly attributed enrollment drops to the law. Though the housing slump and seasonal economic factors make it difficult to pin down how much is attributable to the new law, illegal workers say employers are checking papers and are less inclined to hire them.
“They started asking everybody for papers one day, and those like me that didn’t have them were fired,” said Luis Baltazar, a Mexican immigrant who worked for a paving company until a few weeks ago and was soliciting work at a day labor hiring hall here.
Another immigrant, Jose Segovia, said work had plummeted in the past few weeks, more so than in the four previous Decembers he spent in Phoenix. “Some of my friends went back to Mexico,” Mr. Segovia said, “and I am thinking of going, too, if it doesn’t get better here.”