Federal pay has about doubled in the past 11 years. Uncle Sam now pays about $4 billion each month to roughly the same number of white-collar workers who got $2 billion in 1967.

Government salaries are the bulwark of the Washington area's economy. Federal white-collar workers alone pump $640 million into the local life support system. Yet that same recession-proof guaranteed income is in large part responsible for the high price of housing, food, parking lots and whatever in Washington.

Despite the dramatic jump in federal play, the average employe is little better off than he or she was in 1967. Then it was possible for a Grade 7 to buy a home. Not now. While gross pay has doubled for the average federal worker, the value of each of those salary dollars has shrunk to 49.8 cents.

Within the past decade the government began a program of "comparability" (trying to keep even with private industry). The strange and complicated pay-fixing system has never worked exactly as planned.

Bureaucrats claim their annual pay adjustments are subject to political and economic considerations that don't affect private industry workers. Industry employes say it is a self-adjusting system that has put government employes fincially ahead of most other American salaried employes. Good or bad, the system has produced an "average" federal white-collar salary that exceeds $18,500 nationwide and $22,000 in the Washington area.

Government retirees, thanks to linkage to the cost of living (and a now-defunct pension "kicker",) have received bigger percentage raises. However, their income is still far below that of active federal employees. The average federal annuity now is about $705 a month.

If you want to see where your pay-check has been during the past 11 years, here are the figures. Bear in mind these are straight or average percentage increases. They do not include the value of compounding, which pushes the worth of the increases much, mich higher.

White-collar workers got a 4.5 percent raise in October 1967, a 4.9 percent increase in July 1968 and a big 9.1 percent raise in mid-1969. That was designed to bring most up to the "comparability" level of industry. Later in December 1969, there was another 6 percent raise, then a 6 percent boost in January 1971. January 1972 saw a 5.5 percent raise; October 1972. 5.1 percent; October 1973, 4.8 percent; October 1974, 5.5 percent; October 1975, 5 percent; October 1976, 7.1 percent, and last October, 5.5 percent.

In 1967 a Grade 5 employe's starting salary was $4,565; today it is $10,507. GS 7 paid $6,734 in the first step 11 years ago; today it is $13.014. The Grade 9 starting rate of $8,504 has gone up to $15,920. Today a Grade 13 begins at $27,453. Eleven years ago it was $13,507. Grade 15 now starts at $38,160 and goes to $47,500. In 1967 the same grade rangeed from $18,404 to $23,921.

Federal pensions are linked to the Consumer Price Index. Retirees now get raises each March and September. Previously, they were under a complicated system that had their raises lag far behind actual living cost increases with a corresponding 1 percent "sweetener" added to each raise to compensate for the delay. Congress dropped that plan several years ago. Pension increases look like this:

In 1968 a 3.9 percent increase; in 1969, 3.9 percent and 5 percent; 5.6 percent in 1970: 4.5 percent in 1971; 4.8 percent in 1972; 6.1 percent in 1973: two raises in 1974 of 5.5 percent and 6.3 percent, two again in 1975, 7.3 percent and 5.1 percent; a 5.4 percent raise in 1976; 4.8 percent and 4.3 percent in 1977; 2.4 percent in March of this year and a 4.9 percent raise effective last September. Under the new Consumer Price Index it appears retirees next March will get another raise of at least 2.8 percent.

The Carter administration is looking for a new way to adjust federal salaries. Many White House advisers think the current system is bad. They see no need for a national pay scale for many clerical jobs, since industry pay varies. The president wants to tie government pay to local industry levels.

If Congress approves the local federal-industry wage link, some government employes will do better in future. Some, particularly those in small towns where wages are lower, will get smaller future increases.

Whatever they do with the system, federal workers hope that any doubling of pay in the next decade isn't offset by payment in half-dollars instead of real dollars.