What has the much-publicized 148-nation UN population conference in Mexico City, and its 88 recommendations, actually achieved? Talks with a cross section of delegates reveal solid agreement that ''all systems are go'' in the effort to slow down accelerating population growth in the third world by more voluntary family planning.
With the smoke of the final political battles over disarmament and the Mideast clearing away, clear outlines of consensus on population are appearing. The outlines were visible even before the last-minute decision of the Reagan administration to agree to every recommendation except an Arab-backed one on the Mideast and Soviet-supported wording on disarmament.
''The next step,'' said the executive director of the United Nations Fund for Population Activities (UNFPA), Raphael Salas, who organized the session, ''is to reap the psychological harvest'' - by raising new finances to support family planning.
In a Monitor interview, Mr. Salas appeared confident he could find more money for the UNFPA. The current UNFPA budget is $140 million a year, of which the United States provides $38 million. UN officials hope for an overall increase of 9 to 10 percent a year now, and a US contribution rising to about $46 million annually.
The debates here in Mexico City were not on whether family planning was a good idea, but on what methods were the best to adopt. Particular stress was laid on doing more to provide education, jobs, and status for African, Latin American, and Asian women. This theme is likely to receive even more attention at a major UN conference on the role of women, to be held in Nairobi in July next year.
* ''The conference showed that there are now no racial, ethnic, cultural or religious bars to family planning,'' said Rep. James Scheuer (D) of New York, who came to Mexico City with five other members of Congress to attend a follow-up meeting of parliamentarians.
''All systems are now go. The political issues that got so much attention here were actually irrelevant to the main conference.''
The US was almost alone in its effort to stress free-enterprise incentives above family planning. A number of delegates agreed that free enterprise and initiative were preferable to state-controlled economies. They agreed that over a period of 150 years or so, the US had shown the world that rising incomes do in fact cause lower birthrates. They agreed that coercion was to be deplored and that abortion was regrettable and distasteful.
But African and Asian delegates in particular felt that the US recipe would take too long to work unless accompanied by intense, short-term, voluntary family-planning programs. They also saw an essential role for governments, at least in the immediate future.
Despite these differences, delegates said that consensus on population was unaffected. Mr. Salas believes that consensus here will remain solid partly because all sides can claim that at least some of their own views were reflected.
The Reagan administration can tell right-wing supporters it: (1) fought hard against abortion in Recommendation 18, which says abortion ''in no case should be promoted as a method of family planning''; (2) opposed the Soviet line on disarmament; (3) included the term ''entrepreneurial initiative'' in another recommendation; and (4) included some optimistic phrases about third-world progress.
Developing countries can point to weakened language on these points from original drafts.
Arab countries can say they won the day against Israeli settlements on the West Bank.
Moscow can say it prevailed on disarmament language over US protests.
The Vatican can say it inserted the language on abortion, won a new emphasis on the role of the family, and opposed providing contraception to adolescents.
''Mexico City has set targets for life expectancy (at least 60 years by the year 2000) and infant mortality decline,'' Mr. Salas said in an interview.
''In the final Mexico City Declaration, we stressed the need to solve the problems of overcrowded cities, and about more rights for women. And I hope that a third-world conference will be called in 1994.''
Noting that many blamed US antiabortion, anti-Arab, and pro-free-enterprise attitudes on Reagan's need to placate the far right in his reelection campaign, a participant noted wryly: ''And 1994 is not a presidential election year, either.''