There may be arguments over whether a particular approach to immigration reform is more or less effective, more or less burdensome to non-Europeans, or more or less unfair to such easily identified legal immigrants as Hispanics. But there seems to be a consensus that something needs to be done to repair America's immigration law.

Julian L. Simon has another view: It ain't broke.

The University of Maryland professor of business and social science won't put it that inelegantly, of course. But he does believe that attempts to fix immigration law are based on faulty premises: that the total number of immigrants illegally in this country is huge and growing; that these immigrants, and especially the illeals, take jobs that otherwise would go to jobless Americans, and that they are a drain on the U.S. revenues.

That last premise is easiest to debunk, he says, citing studies that show an average immigrant family (as of 1975) put some $1,500 more into the public coffers each year than it took out.

Nor, he argues, are the illegals about to crowd Americans out of house and job. "What gets overlooked is the fact that a large proportion of the illegals are temporaries. They come here, work for a brief time and then go home. When you take into account both the coming and going, you are talking about a very small net increase. In fact, the National Research Council says the net gain is close to zero, with just as many going as coming."

But since immigrants, legal and otherwise, tend to come to America to find work, and since the illegals tend to seek entry-level work (the legals are disproportionately skilled professionals), wouldn't Sion agree that they must take jobs away from Americans who need them?

He would not. It is a mistake, he says, to think of the gross national product as a fixed number to be divided among a larger number of people as immigration increases the population. "Immigrants don't just take jobs; they also purchase goods and services, thereby enlarging the market, while adding to the national productivity, and they also bring their brains and their creativity. Immigration helps rather than hurts the economy."

Then would Simon argue for opening up the gates and letting whoever will come in? Don't tempt him.

"I'm not prepared to go that far, because we don't have sufficient information. I can say this: All the evidence shows that immigration at present levels is beneficial (to the economy). And it has been beneficial at all levels previously known, including the period when it was six times what it is now. The present level is beneficial. Doubling it would be better. It's like putting fertilizer on your lawn. Some fertilizer helps, more can help more, but there is a level at which you burn up your lawn. Maybe something like that could be theoretically true with immigration; we just don't know."

Simon acknowledges that workers in particular areas of employment -- he mentioned medicine and agriculture -- may suffer some competitive damage for a brief period, but even these will benefit as immigration boosts the general economy, he says.

His is not exactly a unanimous view. A Rice University professor, Donald L. Huddle, recently reported on research that he said shows illegal immigrants taking thousands of jobs from Americans. First, said Huddle, the notion of illegals' taking only stoop-labor jobs is misleading. Many, in fact, are skilled and semi-skilled workers earning upwards of $5 an hour -- jobs that American workers presumably would want.

More important, though, is the damage illegal aliens do to entry-level natives, he said. During labor-short periods (wartime, for instance) "American employers, contractors and recruiters never hesitated to break through the barriers of structural uenemployment -- and substructural isolation -- to hire minority workers." But with the influx of illegals willing to work uncomplainingly at substandard wages, low-income Americans are no longer "being courted, recruited and uprooted from inner- city settlements and slums and brought into the job market."

Simon dismisses the Huddle survey as geographically limited, anecdotal and "totally unscientific."

Maybe. But to my limited and unscientific mind, Huddle seems to make more sense than his rosy-eyed critic.