The Greater Washington Board of Trade and its retail bureau, in particular, were obviously trying to sell something the other day in releasing the results of a new survey highlighting the strength of the area's retail industry. Now that the board has completed its sales pitch, two basic questions remain unanswered: What was the board selling and why?

The effort appeared to be aimed more at the region's lawmakers than at consumers and investors. A comment by Robert Vandermark, this year's chairman of the Board of Trade's retail bureau, was more revealing than the compilation of sales and employment statistics presented at Wednesday's briefing. Expressing some doubt about how the retail industry's role in the economy is perceived, Vandermark said he hoped the survey would be a valuable tool for local politicians in their decision making.

There is the answer to the what and the why. As a tool for anything else, the survey has little value. It contributes little to a long list of surveys and studies that have documented what most Washington area residents know quite well: The retail sector has been, and continues to be, a major contributor to the growth of the region's economy.

Just last summer, the Greater Washington Research Center reported that retail sales in the Washington area rose sharply during the first part of the 1980s. The growth rate, which measured almost 40 percent, was the third highest among the 10-largest U.S. metropolitan areas, according to the Census Bureau, the GWRC reported.

"The growth confirmed the area's continued vitality, despite recent shifts in its economic base," the research center concluded.

Suburban jurisdictions as well as the District registered gains in retail sales between 1980 and 1983, according to Sales and Marketing Management magazine.

According to the D.C. Department of Employment Services' 1985 planning report, the outlook for wholesale and retail trade employment in metropolitan Washington through 1990 is "quite optimistic." The strength of those two sectors is reflected in the department's expectation that they will "offer more new jobs (about 80,500) than any industry in the metropolitan area except services."

Even though retail trade is a major employment sector, recent figures compiled by the DCDES and consultants retained by the GWRC show that the services sector is, by far, the largest provider of private-sector jobs in metropolitan Washington.

(The DCDES compiles labor market information for the District as well as other jurisdictions in the Washington Standard Metropolitan Statistical Area.)

An economic profile prepared by the Washington-Baltimore Regional Association last spring showed that the combined metropolitan areas rank fifth in total retail sales ($31.9 billion annually) and have the highest median household effective buying income ($30,200) in the United States.

Indeed, the demographics of the Washington area -- high income, a high percentage of young households, the largest concentration of government activities and a relatively stable economy -- are responsible for the explosive growth in retail employment and the steady influx of retailers to the area. For a decade, at least, major out-of-town retailers have been describing this as one of the hottest retail markets in the United States.

So, why another survey, and why is the retail industry here adopting a Rodney Dangerfield complex?

"We believe the retail industry has been taken for granted in the Washington economy," Vandermark commented.

By whom? Surely not developers of retail space.They're building retail space at a record clip in commercial projects. In fact, the hiatus in construction of major shopping centers appears to be over.

Consumers certainly don't need to be convinced of the importance of the retail industry to the economy. The robust retail sales reported in the survey are the best measurements of consumer attitudes about the importance of the industry.

Vandermark's assessment of the Board of Trade survey as a tool for politicians overshadows all the PR asociated with the endeavor.

According to a story in yesterday's editions of The Washington Post, local retail executives recalled that the industry has been trying for years to repeal blue laws that ban many Maryland stores from opening on Sunday. At the same time, some officials used the occasion to boost the industry's campaign to persuade lawmakers in the District and Maryland to pass laws that would impose civil fines as well as criminal penalties on bad-check writers.

As a tool, the survey may be more valuable for lobbyists than for politicians.