The concept of "excess death" may sound metaphysical, but American Health has given it a statistical calculation and a disturbing social context. About 75,000 black Americans die every year who wouldn't, were all things otherwise equal. As the magazine points out, that number is "more than three times the total number of AIDS deaths reported last year. And it's nearly one-third of the total number of black people -- almost 255,000 -- who died in 1987," the last year for which numbers are available. The numbers for illness among African Americans are equally dramatic and deplorable, and equally disproportionate racially.

The causes of excess morbidity and mortality are not terribly surprising. Drugs and drug-related violence, AIDS and malnutrition are significant factors in certain areas. A third of the excess, according to a recent Journal of the American Medical Association study, can be traced to six risk factors: high blood pressure, high cholesterol, obesity, diabetes, smoking and drinking. Low income, according to JAMA, accounts for another third. The final "unexplained" third, American Health speculates, may be the stress of racism.

This excellent November package on "Forgotten Americans" also takes Frank Clancy down the "stroke belt" from North Carolina to Louisiana in search of the medical care a few heroic physicians are trying to give some of the country's poorest and thus unhealthiest blacks, and then to Los Angeles to assess the frustrating predicament, a quarter century after its founding in the aftermath of the Watts riot, of Martin Luther King Jr. Hospital, a godsend to the community but "so overwhelmed and underfunded that it fills but a fraction of the needs its founders had hoped to address."

The African American general-interest magazine Emerge devotes a long and comprehensive November cover story to a key subtopic: the fact that AIDS strikes blacks far out of proportion to their numbers in the population. The rate is accelerating as new cases are diagnosed, and black women represent a growing share of the infected population. Because the early emphasis of prevention and treatment was on the white homosexual male population, explains Angela Mitchell, the virus among other high-risk groups, like IV drug users, was allowed to proliferate. Mitchell also points to a persistent pattern of denial about AIDS among African Americans, notably by their otherwise active and influential churches.

Broom Service The Washington Monthly's Scott Shuger has plenty of advice to offer Sharon Pratt Dixon. The gist of his November memo to the likely next mayor of Washington is that Dixon should keep and even expand her campaign promises to cut the municipal payroll, and do it quickly.

Shuger's is a bracing charge, even if (perhaps because) it ignores -- as Dixon would at her peril -- the institutional resistance to disbanding a vast system of patronage. He has some sound advice (don't put off tough decisions, don't just rely on paper, don't be afraid to hire more people where needed) as well as novel suggestions, such as conscripting some of the 3,100 federal cops for high-crime patrol duty.

Shuger makes some telling comparisons about the way other cities and private companies are managed, and in so doing refers repeatedly to bureaucratic "chiefs" and "Indians" and the optimum "C/I" ratios between them. Another sentence about D.C.'s parking meter enforcers refers to "Teutonic precision." Surely in 1990 less freighted terms must have occurred to him.

The World of the Briefcase Like Forbes before it with the antic Forbes FYI, Business Week is going into the lifestyle magazine business. Assets, which appears this week on newsstands and in a little more than half of Business Week subscribers' mailboxes, has been spun off from the popular Personal Finance section of its parent magazine.

Assets has its own very executive identity, clean-cut, understated and male. It's more solemn than Forbes FYI but more relaxed and colorful than Business Week. The editorial mix of issue one (November/December) includes celebration of successful business persons, keys to becoming a successful business person, ways to invest the successful business person's earnings, and things to drink (or drive, or read, or visit, or wear) while being a successful business person. Also, how to choose a nursing home. Subscriptions: $12, six issues. Write Assets, Box 655, Hightstown, N.J. 08520-9339.

In other news from the men's room, Murdoch Magazines has decided to pull the plug on its recent entry in the field, Men's Life, after just one issue.

Of Time and the Revel Time gets on the special-issue bandwagon this week with "Women: The Road Ahead." An "extra" issue of the magazine (the regular edition, dated Nov. 5, carries excerpts from Ronald Reagan's autobiography), this one on the state of womankind follows Newsweek's recent special issues on "The 21st Century Family" and "How to Teach Our Kids." However much or little they add to the Niagara of words on these topics, these extras are proving to be reliable generators of extra cash from advertisers (Sears owns the Time special exclusively) and are popular on the newsstand to boot... . Halloween revelers who want to keep partying with the departed might hop a plane to Mexico City just in time for the Day of the Dead, also known as All Souls' Day, Nov. 2. Or read all about it in Malcolm Lowry biographer Douglas Day's piece in Natural History (October), which also presents, such seasonal ghoulies and ghosties as "The Real Vampire: Forensic Pathology and the Lore of the Undead."