Who faces the brightest quality-of-life prospects for the year 2100 Japan with a population projected to decline by nearly 60 percent, or the United States, whose present population will soar past three-quarters of a billion under current policies?

American news media almost gloatingly report the soft and restructuring Japanese labor market even as our own sets employment records. Japan's recorded unemployment rate is approaching a post-World War II record of 5 percent. A million laid-off workers are still unemployed while millions more have entered the uncertain world of temporary or part-time employment. Only a third of last year's college graduates are full-time employed.

Its salvation lies in a reality rued by demographically unschooled journalists and male politicians Japan's post-war roller-coaster in births. The small numbers born during 1930-45 yielded to two postwar birth peaks - 2.7 million in 1947 and 2.1 million in 1975 - and two birth valleys - 1.5 million in 1955 and 1.2-1.3 million in the 1990s. Those of traditional working age will soon shrink in numbers. Meanwhile, life expectancy gains for adults mean they can expect to live 20 years beyond age 60, the normal retirement age.

Years of high fertility followed by many years of low fertility will result in more than 20 percent of the population in 2010 being age 65 or above, compared with a projected 13 percent for the United States. Retirees will soon outnumber new labor entrants. Unless fertility or immigration shoot up, it may then drop to as few as 50-55 million by the year 2100. Regaining the country's 1920 level of population will ultimately deliver Japan from an ecological dilemma.

Sustaining its peak population, let alone a growing one, would wreak havoc. Pension specialists overlook both the expenses a baby boom imposes and the gains of a baby bust in industrial society. Baby booms require heightened investments first in schools, then in job creation, and in housing and infrastructure expansion. A baby bust sharply and swiftly reduces the youth-dependency burden, enabling parents and society to invest in more per child while freeing up resources for other uses, including old-age supports.

University of British Columbia regional planner William Rees and his associate Mathis Wackernagel, now with the think tank 'Redefining Progress,' originated the concept of an 'ecological footprint.' This is the land-equivalent required to generate the renewable resources a country consumes and recycle its wastes. With one-quarter hectare of productive land per capita, Japan has an 'ecological footprint' conservatively estimated as at least two hectares. Its consumption exceeds production eightfold. Despite intensive agriculture, Japan is the nation most dependent upon food imports. Since 1970, its dependency upon imported cereals has risen from 55 to 75 percent while its population has grown 20 percent.

With a population of 55 million, Japan could shrink its ecological footprint, aim for food self-sufficiency and reduce its food bill.

Huge post-1950 increases in Japan's urban population resulted in housing notoriously inferior to that of other industrial nations. The Japanese themselves applied the expression 'rabbit warrens' to their expensive, tiny, high-rise apartments located hours out of town. This situation will flip-flop. Succeeding generations will enjoy rosier housing prospects in both quality and affordability.

Women, especially married women, currently confront employment discrimination and the full burden of household responsibilities. Young women in a society with a dearth of labor force entrants will gain bargaining chips vis-a-vis both potential employers and potential husbands. Young couples will gain the power to renegotiate the present work 'day' that shortchanges home, spouse and family. Japan's fertility should then rebound to the replacement level.

In the U.S., births to immigrant women have offset the beneficial effects of the birth dearth to baby boomers. The former boosted 1990s' births by 25 percent, frightening for a country that ecologists say has exceeded its maximum carrying-capacity population of 150 million since 1950.

Scientists and large majorities of Americans surveyed want population growth stopped. Yet, our growth-vested politicians confront with equanimity a year 2050 population of a half- billion! On this path, the U.S. will lose food self-sufficiency by the year 2040, according to Cornell University ecologists David and Marcia Pimentel. Global warming is only one of several looming ecological disasters.

With population reduction inevitable in the next century, Japan has a bright future. By the year 2100, Americans will apply the words 'bright and shining' to their past, not their present - and certainly not their future.