The Conference Board's measure of consumer confidence edged up in December, adding to November's gain, the research group reported Tuesday.

The December 102.2 reading of the board's monthly index (beginning from 100 in 1985 when the survey began) is up nearly two points for the month and is at its highest level in four and a half years.In the December survey, the 5,000 U.S. households polled indicated they are substantially more positive this month than in November in their appraisal of present economic conditions, but their expectations have changed very little.

"Consumers enter the new year in high spirits, as the economy continues to perform well," said Fabian Linden, executive director of the Conference Board's Consumer Research Center.

"Unemployment has fallen to its lowest level in more than four years, and inflation continues to be almost imperceptible. These two measures are among the most important factors affecting consumer confidence. The latest survey readings strongly suggest that 1995 should be another good year for the U.S. economy."

Regarding current business conditions, the public's view has not changed much, the survey shows. Slightly more survey participants than previously say conditions are "good," but there was also an increase in the number reporting they are "bad."

But the consumer's evaluation of job availability continues to improve. The number of people who say jobs are "plentiful" is up moderately, while the number complaining jobs are "hard to get" is down substantially.

Looking ahead six months, consumers remain hopeful about the general business outlook. As in November, optimists outnumber pessimists by a ratio of more than two to one.

Regarding future employment prospects, there was little change from last month. Respondents who fear there will be fewer jobs in the months ahead continue to outnumber those who expect more jobs.

In assessing their own families' income prospects for the months ahead, optimists outnumber pessimists by a wide margin.