It never fails that when I write about the problem of population, someone always refers me to the works of people who have 'proved' that there is plenty of food and plenty of space for several billion more people than exist today.

Not to be too blunt, but that's hogwash. Statistics describe - they do not prove anything - and theoretical models are in practical terms hokum. That's because the world does not exist as a theory. It exists in a finite amount of rock and dirt and water. Nor do people exist in theory. They exist in individual bundles of flesh and blood in specific places in specific circumstances at a specific point of time.

The fact that not many people live in Nebraska doesn't add an inch of living space to a family of 12 crowded into one room in Cairo, Egypt or Rio de Janeiro, Brazil. The fact that American grain prices are low and the storage bins are overflowing doesn't put an ounce of food in the mouth of a starving child in the Sudan. The fact that there is plenty of room to build more housing doesn't move one desperate child off the lethal streets of Rio. Street kids there have become so numerous that occasionally businessmen have hired assassins to kill them where they sleep. People in one poor area of Brazil were discovered eating the flesh of human bodies tossed in a trash dump.

Let us chuck theory and deal with the world as it is, not as we would like it to be and certainly not as, in theory, it might be. The world, like a used car, comes 'as is.'

Those who do not think overpopulation is a problem should visit the U.S.-Mexican border, where they can see with their own eyes one effect of population exceeding carrying capacity. That effect is migration, the steady movement of people from places where they can't live decently to places where they believe they will have a better chance of surviving.

And if you think migration isn't a problem, you should consult any Native American and ask him or her what the effects of migration are. A small number of Europeans didn't steal the Indians' lands. The Indians just drowned in a tidal wave of European migration. Those Europeans came to North America for the same reason Mexicans, Central Americans and Chinese are coming to North America.

More than two decades ago, executives of a large seafood restaurant chain predicted the price of seafood would go far higher than beef. Why? Because the fishes of the sea are being fished out. This one restaurant chain in the United States was forced to buy from the four corners of the world just to supply its own customers in the United States.

I had asked them if they ever bought from Japan, which has one of the world's largest fishing fleets. 'Oh, heck no,' was the answer. 'The Japanese use every scrap they catch.' The boundless sea is no longer boundless because population pressure is causing it to be polluted and overfished. And the prediction about prices proved accurate.

I don't think abortion and sterilization are the answers - though, by all means, contraceptives should be widely available. The difficult answer is a human-oriented, rather than corporate-oriented, form of economic development. Today's international aid and economic development models are both corrupt and designed to benefit corporations, not people.

A good book on this point is The Road to Hell The Ravaging Effects of Foreign Aid and International Charity. The author is Michael Maren, and the publisher is the Free Press. Maren is no conservative ideologue dealing in theory and dogma. He's a liberal, a veteran of the Peace Corps, Catholic Relief Services and USAID. He writes from personal experience, and what he saw will enrage any decent person. As I said, let's junk theory and deal with reality.