A new law in the US state of Arizona that took effect on 1 January 2008 will punish employers who hire workers without valid US residency. Advocates of tough US immigration measures say the law - which is restricted to just the one state at present - may provide answers for the whole nation.

The state's new law is seen by some as a model for the US, and as a recipe for disaster by others.

Being a border state, Arizona leads the US in illegal hirings. Estimates say between 10 to 12 per cent of the workforce comprises illegal aliens, mostly from Mexico. The state has only 6.2 million people, but is estimated to have more illegal immigrants than Illinois or New York.

Alien explosion
Two-thirds of Arizona's foreign-born population are not in the US legally, say experts, and the vast majority of them live in relative poverty. The state's social services have been overwhelmed in recent years by a flood of migrants evading tighter border security in California and Texas.

Politically conservative commentators say the state, if things continue as at present, may represent the United States of the future. They say much more needs to be done to address the problem of both illegal (too much) and legal (too little) immigration. Since 2000, the US has seen its highest increase in immigrants, but more than half are estimated to be illegal.

De-magnetisation
Arizona's new law says it aims to go after the prime magnet for illegal border-crossers - companies that offer jobs without checking an applicant's legal status. The new law allows authorities to revoke the business license, if the employer is caught more than once with illegal workers (including those with fake documents).

The US Homeland Security Department is working on a similar enforcement effort. But it has barely got off the ground. A bill seeking to confer legality on some illegal aliens and confer amnesty on others while cracking down on illegal border-crossers failed in Congress after opposition from conservatives.

Enforcement, etc
But, say, the proponents of the new law, its success depends on how it is enforced. If employers and law-enforcement officials use racial profiling to crack down on illegal workers, it is bound to backfire.

Besides, an acceptable level of leniency is required in the use the federal 'e-Verify' database, new nationwide system for checking workers' legal status. The problem is, the database still has an unsatisfactory error rate, which can harm legal workers. The state must also act to prevent a new type of black market in 'off-the-book' hires.

The law has already withstood an initial legal challenge in federal courts, but its big test will be seen in its effect on the state's economy. Arizona's agriculture, service, and construction industries depend greatly on illegal workers as a source of cheap labour. The average household income of illegal immigrants in Arizona is $35,000 per year, whereas for citizens it is $69,000.

Will it work?
The critical question is, will businesses be able to afford the higher wages they need to offer to attract legal workers, and still stay in business? If not, the state may see a slump in agriculture, as businesses move out of the state.

One early indicator may be the price of lettuce. About half of the USA's winter lettuce production comes from around Yuma. If legal lettuce pickers have to be paid higher wages, salads will cost more countrywide. Or, lettuce companies may decide to grow their lettuce elsewhere.

But proponents of tough new measures feel otherwise. Some economists feels that if farm wages rise, it will force a move towards greater mechanisation and, consequently, increased productivity in farming, without significantly raising prices for produce.

Besides, they point out, a recent Congressional Research Service survey has concluded that there was no "nationwide shortage of domestically available farm workers".