ANAHEIM, CALIF. -- It's come to this: Mickey Mouse and Snoopy duking it out. Disneyland and Knott's Berry Farm, the two enormous amusement parks that have long symbolized Orange County's fairy tale prosperity, are waging an ominous price war. Knott's, whose mascot is Snoopy, cut its admission charge 40 percent in December. Disney responded with discounts of 11 percent for kids and 27 percent for adults who are Southern California residents.

In big ways and small, economic reality has intruded into what has been one of the country's most robust local economies. Consumers who once opened their hearts and wallets to the thrills and delights of life in Orange County have grown more cautious. Consider:

Last month, the state reported that retail sales had fallen in 13 of the county's 29 cities even before inflation was considered.

The county's biggest industry, construction, "practically ceased to exist by the end of {last} year," according to Lucien Truhill, president of the county Chamber of Commerce.

The Chapman College Economic and Business Review reported recently that the decline in defense spending here "has been more severe in the county than in either California or the nation." Doing business here are Hughes Aircraft Co., McDonnell Douglas Corp. and Rockwell International Corp., all companies that have recently suffered from major project cancellations.

Still, bad times in Orange County are not so bad in some respects. The November unemployment rate of 4.1 percent was 2 percentage points below the state and national jobless rates. Median income is still a stratospheric $56,380 and the county still has splendid weather, a high-technology industry rivaling Silicon Valley and, in the words of Chamber of Commerce President Truhill, "42 miles of the most gorgeous coastline in the world."

When the winter sun is dipping dramatically into the Pacific Ocean off Huntington Beach at the end of another warm day, it is difficult to remain pessimistic for long. James Doti, author of the Chapman study, predicted an "extremely mild" recession during 1991. And even now there are bright spots shining through the gloom of construction slowdown and defense industry cutbacks.

Last June, California voters, tired of the daily gridlock on the state's infamous freeways, approved a massive transportation program that includes an eventual 9-cent rise in the per-gallon gasoline tax. Then in November, after two previous failures, the residents endorsed a half-cent increase in the local sales tax to widen the Santa Ana Freeway that connects much of the county to Los Angeles and make other road improvements.

"That is money that is going to be pumped into our transportation sector, engineering and road construction," said Bob Smith, the county government's chief economic forecaster.

Mark Baldassare, a sociologist at the University of California at Irvine who follows economic trends, said, "It is quite ironic that a county that has prided itself on fiscal conservatism and 'no' on taxes is getting all this new construction because of taxes."

Another bright spot is the county's much broader high-tech industry. "We are more diversified than we used to be," Smith said. Some biotechnology companies are doing well and some electronics firms are finding a profitable export business, with none more successful or more illustrative of the powerful immigrant surge here than Irvine-based AST Research Inc. The three founders, two born in China and one born in Pakistan, mortgaged their houses for $12,000 in cash and added $28,000 in equipment to start the company 11 years ago. Last year, AST stock more than doubled in value as the company logged in $534 million in sales of its personal computing equipment. Co-founder Tom Yuen attributes AST's success to "sound business fundamentals, keeping an eye on costs and inventory."

The area's current economic woes, Yuen said, appear to be part of the usual boom-and-bust construction cycle. "I feel we have overbuilt," he said of the ailing local real estate industry, "and it will take a couple of years to come out of it."

One big real estate development firm, the Irvine Co., announced in November it was cutting 40 of its 370 jobs, but it emphasized that its leasing business was still healthy in many areas. The company also said it would continue projects already in development, including 1 million square feet of office space and Newport area hotels and homes.

The banks here appear healthy, particularly when compared with other areas of the country such as New England. Doti said his analysis showed that in nearly every year of the 1980s, the growth of building permits exceeded population growth in the Boston area. In Orange County, population generally has increased twice as fast as building permits, creating one of the most expensive housing markets in the country but also ensuring against a disastrous level of overbuilding.

"While our 1991 forecast would meet the technical definition of recessionary activity," Doti said, "such a recession would pale in comparison to the severity of previous Orange County recessions."

One reason is the county's still-healthy reputation in the back streets of Guadalajara and the tea houses of Taipei. The cost of housing, the crowded freeways and the persistent air pollution has led many native Americans to leave. Out-migration of non-Hispanic whites from the county has exceeded in-migration by 4,000 annually.

But the net inflow of Hispanic immigrants, about 11,000 a year, and Asian immigrants, about 8,000 a year, has more than filled the gap, creating a strong demand for retail services and products that bolster the local economy. These immigrants often bring with them useful skills, life savings and, in many cases, an impulse to start their own companies. In addition, there are uncounted illegal immigrants who create enough economic activity that local government officials have gone to great lengths -- setting up hiring halls, discouraging immigration agent raids -- to keep them living and working in Orange County.

"There's still a labor shortage," said Doti. "Immigration is one of the most important strengths we have, and ... there really isn't a downside to it, so far."