Which do you want to hear first, the good news or bad news?

The bad news is that advertisers are going to spend less than originally forecast this year. The good news is, for most media that rely on ad dollars to stay afloat, it's going to start getting better soon.So says the advertising industry's chief forecaster, who has just finished analyzing 1990's dismal results.

Ad spending is expected to rise 3 percent to 4 percent this year. That's on par with the 3.8 percent gain in 1989 but still less than the overall rate of inflation, says Robert J. Coen, director of forecasting at McCann-Erickson Worldwide.

Advertisers should spend more than $132 billion this year, but they aren't likely to dole out the $136 billion forecast last December. Coen said advertisers slashed budgets in the closing months of 1990, probably because of rising tensions in the Persian Gulf and the recession.

"Christmas was terrible in 1990," Coen said. "You might say the retailers just gave up on Christmas. There was no advertising."

As a result, newspapers experienced their worst year since 1961. Their ad drought was made worse by declines in classified help-wanted and real estate ads.

So far this year, media reports have been gloomy, with first-quarter ad revenues off from 2.8 percent at newspapers to 6.8 percent for local television stations.

He doesn't expect it to get any better until the end of summer.

Economic recovery, pent-up consumer demand, political elections and the 1992 Olympics all should ignite an ad spending boom that will continue for most of the decade, he said.