If there were a truth-in-government award, it might go to the Council of Economic Advisers for its annual report. To be sure, the official economic projections are relatively optimistic, but the supporting text is something else again.

The CEA report often reads like a brief for the loyal - but skeptical - opposition. In their gloomier moments, CEA members must believe they are living on borrowed time: a period of tranquility before the turbulence.

For the economy treated President Carter gently in his first year. It created no major crises, achieved respectable progress (4.9 percent growth and a drop of one percent in the unemployment rate) and caused only modest embarrassment (a sulking stock market). But, looking ahead Carter's economists worry. Can the anti-inflation plan work? Is Humphrey-Hawkins possible without higher inflation? And will the current recovery last?

The CEA's anwers are not reassuring.

The anti-inflation program is the most pressing issue. The program - which envisions informal efforts to convince labor and business to hold wage and price increases below 1977 levels - aims at achieving a 0.5 percent annual reduction in the inflation rate. Likewise, a ness costs, this is the heart of the program - and also its Achillis' heel.

Achieving the overall reduction, the CEA says, requires a much larger cut in the increases of wages and fringes for key unions. Not only must sizable increases in social security taxes rates be offset, but more important, today's tighter labor markets enable many nonunion workers - whose wages have lagged - to play catch-up. Basically, the CEA says, members of strong unions have experienced wage gains of 8 percent to 9 percent annually since 1975, while workers "in markets composed of smaller parallel goal is to cut the increase in unit labor costs by the same amount (the increase was 6 percent last year). With labor costs amounting to more thn two-thirds of busifirms, smaller unions and unorganized labor" have received smaller increases.

In effect, the CEA is warning that the White House must convince the strongest unions to exercise the most self-restraint.

That doesn't seem likely unless the White House can create a new climate for bargaining. The expectations of rank-and-file members would have to subside, making it easier for union leaders to reach lower settlements without risking grepudiation. And businesses would need to became sufficiently convinced that a new wage pattern is being established to stiffen their will to resist anything above the trend. In the last round, major industries generally acceded meekly to a three-year increase of about 30 percent.

As a practical matter, the administration has about six months to get its labor act together. This year isn't a big one for major union settlements, but 1979 - with the Teamsters, rubber workers, electrical workers and auto workers - is. If the administration is to change the climate, it must do so by the fall, when Teamster negotiations could begin in earnest. A big Teamster settlement would increase pressure on other unions.

The people who ought to be worrying most about this are the 2.1 million federal workers and the 600,000 postal workers - two large groups where the White House can directly influence settlements. Federal workers receive annual pay raises i n October, and the postalcontract expires in July. The White House could attempt to force lower settlements on these groups in an effort to influence 1979 bargaining.

The CEA's second major anxiety is the Humphrey-Hawkins bill, which would set a goal of 4 percent unemployment by 1983. The CEA report says that its estimate of 1983 "potential" gross national product - the amount of output possible without generating new inflation - is consistent with an unemployment rate of nearly 5 percent. Consequently, in the CEA's view, bringing the jobless rate down to 4 percent would be risky. It could mean demand so high that firms easily could raise prices and that skilled workers - facing fierce competition for their talents - could press for sharply higher wages.

The only exit from this squeeze is to increase the skills of the unskilled, enlarging the economy's potential outup and diminishing the inflationary pressures of high employment. But the CEA isn't sure this can be done. It acknowledges that the joblessness of black youths is as bad now as it was at the bottom of the 1975 recession.

Then, the black teenage unemployment rate was 37 percent (against 18 percent for white teenagers); in the fourth quarter of 1977, the rate was 38 percent (against 14 percent for whites). The CEA attributes the disparity to a disproportionate rate of growth in the black teenage population: 3.2 percent annually from 1972-76 against 1.3 percent for whites.

But the CEA has no stock answers for the problem. It dutifully enumerates the administration's initiatives - public service jobs, welfare reform - but the tone is skeptical. It warns particularly against raising salaries for welfare jobs much above the minimum wage. Putting them higher, it argues, inevitably would attract workers who otherwise might find private jobs.

What clearly would frustrate any progress is a stall in the expansion, and the CEA worries that inadequate investment could play the spoiler role. So far, most economic growth has stemmed from consumer spending, government spending and a housing boom. Sooner or later, that must change. Pumping up government spending or consumer spending - through tax cuts - won't do any good if industry can't meet the demand.

At the moment, that doesn't seem a threat. But the CEA did some calculations indicating that if the ecoonmy were now at "full employment," capacity ultilization would be about 90 percent - well above rates that have produced added inflation in the past (actual utilization is now at 83 percent). Thus, the CEA thinks investment must grow faster, or, in a few years, attempts to reduce unemployment further could be self-defeating.

The message here is that the outlook is rife with contradictions. There's nothing unusual about that. Nor does it mean that all the problems inevitably must work out for the worse. What is intriguing is the openness in acknowledging them. It is almost as if the CEA decided to publish its memos to the president.