MEXICO CITY — President Ernesto Zedillo has a gift in store for the Mexican people: He has promised to keep Mexico's equivalent of the State of the Union address, to be delivered Sept. 1, to within one hour. That's quite a pledge, given that a century ago the informe, as the speech is called, lasted much of a day and recent versions have approached three hours. Yet, as appreciative as rhetoric-weary Mexicans may be, many will be looking for another gift in Mr. Zedillo's speech in the form of an economic-stimulus package to get the country's recession-bound economy moving again. Are Mexicans likely to get what they wish for? Prominent business organizations, labor unions, and consumer groups are asking Zedillo, who took office last Dec. 1, to use his first informe to announce plans to jump-start an economy that, by the government's optimistic estimate, will shrink more than 4 percent over the year. (Some independent economists say the decline in gross national product could approach 8 percent.) On the other hand, some economists say Mexico's positive macroeconomic signs are still too tentative to withstand the inflationary and fiscal impact of substantial new government-spending programs. Zedillo also has to remember the tough fiscal requirements - such as maintaining a budget surplus - set by the financial-rescue plan that the United States orchestrated. The most likely scenario is that Zedillo will refer generally to plans for stimulating the economy, but he will leave the specifics of stepped-up government spending or proposals for reigniting consumer spending for later. ''There's no doubt that the president will use the informe to talk about reactivating the economy over the next few months,'' says Cesar Flores Esquival, president of the National Association of Truck and Bus Producers. ''He knows he has to say something to encourage the Mexican people.'' The announcement earlier this month that the Mexican economy retracted in the second quarter at a whopping 10.5 percent annual rate jolted officials and business leaders alike, and it now seems to be pushing the government more quickly toward some kind of stimulus package. Economic planners want to head off growing complaints that measures taken in the wake of last December's steep peso devaluation - including a 50 percent hike in the country's value-added tax and stratospheric interest rates - were more severe and caused more lost jobs than necessary. National and foreign investors are jittery about prospects for social turmoil. Zedillo knows he must address those concerns, analysts say, if he wants to maintain the flow of investment dollars returning to Mexico. ''Certainly, before the end of the year, it will be time to talk seriously about some economic reactivation measures,'' says Jorge Cambiaso, director of economics at the Center for Economic Research and Teaching in Mexico City. ''But I don't think we are there yet. We still have to be sure we are well on the right track.'' Inflation, expected to approach 50 percent over the year, should be under 2 percent a month before government spending is pumped up, he says. ''But so far, we only have one month [July] at that level. We need to wait and see the results of another month or two,'' Mr. Cambiaso says. Cambiaso lauds the government for its ''success in addressing this crisis in such a short period of time.'' He cites a $3 billion trade surplus for the first six months of the year and $5 billion in direct foreign investment over the same period. But he acknowledges that this was achieved ''at tremendous social cost.'' Too many key factors in building the country's long-term wealth need attention, Cambiaso says. The current trade surplus is fine but mostly a result of lower internal demand, he says. ''Mexico needs to work much harder on developing its value-added exports,'' he says. Other observers point out that part of the money Zedillo might have set aside for some growth-inducing programs was pledged last week in a new $1.1 billion debtors-relief program, which targets Mexico's beleaguered middle class. ''Zedillo's problem is that he simply doesn't have the money to pay for grand new programs,'' Mr. Flores says. To boost public optimism, finance ministry officials point out that the government has more than 60 percent of the budget to spend in the year's second half. But analysts say this is nothing unusual in a new presidency. In any case, many observers - including some economists - insist that even if the economy is the public's primary concern, an incomplete political transition is really Mexico's most important challenge and is the issue that should dominate Zedillo's address.