IN SEPTEMBER 1977 Newsweek reported that "more than 100,000 West Africans perished of hunger" in the Sahel between 1968 and 1973 because of draught. Upon inquiry, the writer of the account, Peter Gwynne, informed me that the estaimate came from Kurt Waldheim's message to the United Nations' Desertification Conference. I therefore wrote to Wadlheim asking for the source of the estimate.

Three mutally contradictory documents came back from the United Nations' Public Inquires Unit:

1. Waldheim's message to the conference saying, "who can forget the horror of millions of men, women and children starving, with more than 100,000 dying, because of an ecological calamity that turned grazing land and farms into bleak desert?"

2. A two-page excerpt from a memo by the U.N. Sahelina Office, dated Nov. 8, 1974, saying, "It is not possible to calculate the present and future impact of this tragedy, on the populations . . . Although precise figures are not available, indeed unobtainable . . . certainly there has been an extensive and tragic loss of life."

3. A one-page memo written for the U.N. by Helen Ware, an Australian expert on African demography, who was a visiting fellow at the University of Ibadan in March 1975 when she wrote it. From calculations of the normal death rate for the area, together with "the highest death rate in any group of nomads" during the drought she estimated "an absolute, and most improbable, upper limit [of] a hundred thousand . . . . Even as a maximum [this estimate] represents an unreal limit."

Ware's statement, which makes nonsense of Waldheim's well-publicized assessment, was on page one of a document written for the U.N. well before the Desertification Conference. Apparently it was the only calculation the U.N. had, and it was grossly misinterpreted.

More recently, the U.N. press releases have retreated to the more modest assertion that "tens of thousands" died in the Sahelian drought. But even this assetion is undocumented. "The problem with deaths in the Sahel," Ware says, " is precisely that there was so little evidence of them -- rather like the photograph of the dead cow which kept turning up in illustration to every newspaper story."

A recent summary of the scientific evidence on the drought's effects by John Caldwell, a demographer who was familier with the area prior to the drought and spent 1973 there, says, "One cannot certainly identify the existense of the drought in the vital statistics . . . nutritutional levels, although poor, were similar to those found before the drought in other parts of Africa. The only possible exception was that of very young children."

This is an example of a common phenomenon: Bad news about population growth, natural resources and the environment that is based on flimsy evidence or no evidence at all is published widely in the face of contadictory evidence.

Another example comes from the same Newsweek piece: "More than one-third of all the land is dessert or near-desert. And deserts are spread- ing inexorably, turning arable land into stony waste or heaps of drifting sand . . . annually destroying 12 million to 17 million acres." The headline on a front-page story in The New York Times said, "14 Million Acres a Year Vanishing as Deserts Spread Around Globe."

Some arable land surely is deteriorating. But these news stories, and the many others originating from the book "Losing Ground," by Erik Eckholm of Worldwatch Institute clearly imply a more general proposition: that the world's supply of arable land is decreasing. Yet the truth is exactly the opposite: Joginder Kumer made a country-by-country survey of the changes in arable land from 1950 to 1960. His finding: There was 9 percent more total arable land in 1960 than in 1950 in the 87 countries for which he could find data (constituting 73 percent of the land area of the world) -- a gain of almost 1 percent per year. And the more recent Food and Agriculture Organiation data show a rise in "arable and permanent cropland" from 1403 to 1507 million hectares in the world as a whole from 1961-65 to 1974, an annual increase of roughly 0.7 percent. In the developing countries the area increased by 1.1 percent annually over the decade 1960 to 1970.

The increase in the quantity of land that is cultivated rose even faster than 1 percent per year -- from 8.9 percent of the total area to 9.9 percent during 1950 to 1960. And the increase ineffective crop area was greater yet, because of the increase in multiple cropping in Asia and elsewhere. In some places the extension of cultivation has reduced the quality of land, of course, but in other places the process has improved the quality of land.

But does not a larger population necessarily mean "more pressure" on the land, so that ultimately everyone will be scratching out there skimpy meals from 18 hours of work a day on a plot the size of a window-box? There has been such a trend in countries that have not yet entered into modernization and industrialization. For example, farm size declined as population increased in Poland from 1787 to 1937 and in China from 1870 to 1930. But the more general trend points in the opposite direction. In all the higher-income industrialized countries in Europe and North America, and in Japan, a smaller absolute number of farmers are producing much more food and feedingmuch larger populations than in the past.

The less-developed countries have not begun this trend, though the relative proportions of their populations that are in agriculture are falling rapidly. We may expect that as they get richer smaller absolute numbers of persons will be doing the farming for larger populations, on ever-larger farm units.

Here are some other examples of publizied, false, bad news and the unpublicized, good-news truth: statement : The food situation in less-developed countries is worsening. "Serious World Food Gap Is Seen Over the Long Run" is a typical headline.

Perhaps most influential in furthering that idea was Paul Ehrlich's best-selling book "The Population Bomb," which begins: "The battle to feed all of humanity is over. In the 1970s the world will undergo famines -- hundreds of millions of people are going to starve to death." Many writers view the situation as so threatening that they call for strong measures to restrict population growth -- "compulsion if voluntary methods fail," as Ehrlich put it.

Fact : Per capita food production has been increasing at roughly 1 percent yearly -- 25 percent during the last quarter century. Even in less-developed countries food production has increased substantially. World food stocks are high now, and even India has large amounts of food in storage. In the United States farmers are worrying about disasters from too much food.

Some countries have done far worse than the average, and have even had declining production, often because of war or political upheavel. And progress in food production has not been steady. But there has been no year, or series of years, so bad as to support a conclusion of long-term retrogression.

Statement : The danger of famine is increasing. The U.N. Economic and Social Commission for Asia and the Pacific predicts "500 million starvation deaths in Asia between 1980 and 2025."

Contrary evidence : the course of famines is difficult to measure quantitatively. But D. Gale Johnson, an agricultural economist who has studied the history of famines intensively, estimates that since World War Ii there has been a "dramatic decline" in famines. Only a tenth as many people died of famine in the third quarter of the 20th century as in the last quarter of the 19th century, despite the much larger population now. A key cause of the decline in famine deaths has been the improvement in road systems, which allow food to be moved from regions of plenty to regions of shortage.

Statement : Higher population growth implies lower per capita economic growth. This has been almost gospel for the World Bank, the State Department's Agency for International Development (AID) and other development agencies.

Contrary evidence : Empirical studies find no statistical correlation between countries' population growth and their per capita economic growth, either over the long run or in recent decades. Contemporary cross-national comparisons of current rates of population growth and economic growth are another source of evidence. Many such studies have been done by now, and they agree that population growth does not have a negative effect upon economic growth in either more-developed or less-developed countries. These overlapping empirical studies do not show that fast population growth increases per capita income, but they certainly imply that one should not confidently assert that population growth decreases economic growth.

Statement : Sophisticated computer models show that for the next 30 years an increase in population causes a decrease in per capita income.

Response : At the heart of all these models is simply an arithmetical truth: An added child, with all sharing a given amount of goods, means there is less to go around. As Wilfred Beckerman remarked, the instant a calf is born, per capita income and wealth go up, but the instant a child is born, per capita income and wealth go down.

Once the children grow up, however, and become producers as well as consumers, their impact on per capita income reverses. Eventually the income of other people is higher because of the additional children. But this takes more than the 25 or 30 years covered by the well-known models.

The contribution of additional people to increasing productivity occurs partly through larger markets and economies of scale. But more important are an additional person's contributions to increased knowledge and technical progress. People bring not only mouths and hands into the world but also heads and brains.

Population growth and productivity increase are not independent forces running a race. Rather, additional persons cause technological advances by inventing, adapting and diffusing new productive knowledge.

I have added this effect of additional people on productivity to a standard economic model. The result is that additional persons, instead of being a permanent drag, lead to an increase in per-worker output starting 30 to 70 years after entry into the labor force.

Statement : Urban sprawl is paving over the United States, including much "prime agricultural land" and recretional areas.

Fact : All the land used for urban areas plus roadways totals less than 3 percent of the area of the United States. And the increase over the half-century starting in 1920 was only 0.00025 of total land annually. The Department of Agriculture says "we are in no danger of running out of farmland."

Each year 1.25 million acres are converted to efficient cropland by draining swamps and irrigating deserts, while 0.9 million acres are converted to urban and transportation use. The rest of the 2.2 million acres of rural land which goes out of use yearly is abandoned not because of "paving over" but because it has "low soil fertility and a terrain unsuited to efficient use of modern machinery." A million acres yearly goes into additional wilderness recreation areas and wildlife refuges, and another 300,000 acres goes for reservoirs and flood control. The danger to agriculture from "paving over" is another bogeyman.

About wildlife areas, state and national parks: These increased from 8 million acres in 1920 to 73 million acres in 1974 and are still increasing.

Statement : We are running out of natural resources and raw materials.

Response : The only meaningful measure of scarcity in peacetime is the cost of the good in question. The cost trends of almost every natural resource -- whether measured in labor time required to produce the energy, in production costs, in the proportion of our incomes spent for energy, or even in the price relative to other consumer goods -- have been downward over the course of recorded history.

An hour's work in the United States has bought increasingly more of copper, wheat and oil (representative and important raw materials) from 1800 to the present. And the same trend has almost surely held throughout human history. Calculations of expenditures for raw materials as a proportion of total family budgets make the same point even more strongly. The prices of raw materials have even been falling relative to consumer goods and the Consumer Price Index.

Statement : Energy is getting scarcer.

Response : The facts about the cost of energy are much the same as the facts about other raw materials. The new strength of the OPEC cartel to control oil price obscures the cost of production. But the production cost of a barrel of oil has not risen, and probably has fallen, in deflated dollars; even after the "oil crisis" of 1973 it was still $0.05 to $0.15 per barrel in the Persian Gulf, which was perhaps a hundredth of the market price. It is reasonable to expect that eventually the price of oil will again return nearer its economic cost of production, and the long-run downward trend in the price of oil will resume its course.

The price of electricity is an interesting measure of the consumer cost of energy, and it is largely unaffected by cartels and politics (though the price of electricity did rise after 1973 because all energy sources, including coal and uranium, jumped in price when the price of oil went up, on account of the improved market power of coal and uranium suppliers). But the long-run cost of electricity clearly has been downward.

In short, energy has not been getting scarcer in basic economic terms, but rather has been getting more plentiful.

Statement : The supplies of natural resources are finite. This apparently self-evident proposition is the starting point and the all-determining assumption of such models as "The Limits to Growth" and of much popular discussion.

Response : Incredible as it may seem at first, the term "finite" is not only inappropriate but is downright misleading in the context of natural resources.

A definition of resource quantity must be operational to be useful. It must tell us how the quantity of the resource that might be available in the future could be calculated. But the future quantities of a natural resurce such as copper, for example, cannot be calculated even in principle, because of new lodes, new methods of mining and variations in grades of copper lodes; because copper can be made from other metals; and because of the vagueness of the boundaries within which copper might be found -- including the sea and other planets. Even less possible is a reasonable calculation of the amount of future services of the sort we are now accustomed to get from copper, because of recycling and because of the substitution of other materials for copper.

With respect to energy, it is particularly obvious that the earth does not bound the quantity available to us; our sun (and perhaps other suns) is our basic source of energy in the long run, from vegetation (including fossilized vegetation) as well as from solar energy. As to the practical finiteness and scarcity of resources -- that brings us back to cost and prices, and by these measures history shows progressively decreasing rather than increasing scarcity.

Statement : The nation's "overall environmental well-being" is declining, according to the Environmental Quality Index (EQI).

Fact : This widely reported index is, according to the National Wildlife Federation, which prepares and disseminates it, "a subjective analysis . . . judgment [which] represents collective thinking of the editors of the National Wildlife Federation staff." That is, the EQI represents casual observation rather than hard statistical facts. It includes such subjective judgments as that the trend of "living space" is "down . . . vast stretches of America are lost to development yearly."

But the objective statistical facts indicate that the environment is getting better. "Living space" is not declining, and recreational areas are increasing rapidly. The official data of the Council on Environmental Quality concerning major air pollutants show sharp improvements in the last decade. With respect to water, "major improvements in the quality of polluted streams have been documented." The most important is life expectancy; it continuses to rise, and at an increasing rate; a gain of 2.1 years from 1970 to 1976, compared with a gain of only 0.8 year in the entire decade of the 1960s.

Statement : "Even if the family size drops gradually -- to the two-child average -- there will be no year in the next two decades in which the absolute number of births will be less than in 1970," said the President's Commission on Population Growth in 1972.

Fact : In 1971 -- the year before this forecast -- the abolute number of births (not only the birth rate) was less than in 1970. By 1975, the absolute number of births was barely higher than in 1920, and the number of white births was actually lower than in most years from 1914 to 1924. This scientific fiasco shows how flimsy are the demographic forecasts upon which arguments about growth policy are based.

Another peculiar forecasting episode: Between 1969 and 1978, U.N. and other standard estimates of the world's population in the year 2000 fell from around 7.5 billion to around 5.5 billion. This is a difference of 2 billion people -- equal to about half the world's present population -- for a date only 30 years or less in the future. There is also grave disagreement even among estimates of current magnitudes. An important example is the population growth rate of China, a fifth of the entire world population: 2.4 percent per year according to the Environmental Fund, 0.8 percent per year according to AID. These estimates correspond to doubling times of about 30 years and about 90 years respectively, estimates with entirely different implications.

Why do false statements of bad news dominate public discussion of these topics? Here are some speculations.

1. There is a funding incentive for scholars and institutions to produce bad news about population, resources and the environment. AID and the U.N.'s Fund for Population Activities disburse more than $100 million each year to bring about fertility decline. Much of this money goes to studies and publications that show why fertility decline is a good thing. There are no organizations that fund studies having the opposite aim.

2. Bad news sells books, newspapers and magazines; good news is not half so interesting.

3. Many people have a propensity to compare the present ahd the future with an ideal state of affairs rather than with the past or with some other feasible state; the present and future inevitably look bad in such a comparison.

4. Some publicize dire predictions in the idealistic belief that such warnings can mobilize institutions and individuals to make things even better; they think that nothing bad can come of such prophecies. But we should not shrug off false bad news as harmless exaggeration. There will be a loss of credibility for real threats as they arise, and loss of public trust in public communication. As Philip Handler, president of the National Academy of Sciences, testified to congressmen in the midst of the environmental panic of 1970: "The nations of the world may yet pay a dreadful price for public behavior of scientists who depart from . . . fact to indulge . . . in hyperbole."