John S.R. Shad, chairman of the Securities and Exchange Commission, is boasting of doing more with less.

At a press preview yesterday, Shad reeled off a summary of the SEC's enforcement record, reporting, for example, that the number of SEC enforcement actions increased 31 percent between 1981 and 1982 despite a 5 percent decrease in total staff years and a budget increase of just 3.9 percent.

In addition, investment company and adviser inspections rose 26 percent in the same period. Moreover, registration and transaction fees from the securities industry offset 94 percent of the SEC's budget last year compared with 81 percent in 1981, thanks to the growth of money market funds.

Shad, who is scheduled to discuss his budget today before the House Appropriations Committee, attributed the gains to continued improvements in automation and a reduction in paperwork through simplification of registration and reporting requirements.

The commission's proposed budget for fiscal 1984 is due to increase by 3 percent to $92 million from $89 million in the current fiscal year. That will mean a reduction of 125 positions, or 6 percent in personnel. Total staff years--the equivalent of a full year's work per employe--will drop to 1,795 from a peak of 1,982 in 1981.

Shad said an 8 to 9 percent increase would have been needed to keep the staff at current levels. The Office of Management and Budget had recommended no increase, but the White House settled on 3 percent. He said all SEC programs would be affected, but enforcement--which now accounts for about one-third of the total budget--would be reduced the least.

Shad also announced that an advisory committee set up to study problems involved in tender offers would make recommendations by next summer. The committee, composed of victims and perpetrators of takeovers as well as academics and other experts, was formed in the wake of congressional and investor outcry last year over capital-consuming takeovers such as the fracas involving Bendix Corp., Martin Marietta Corp. and Allied Corp., and controversial practices such as "golden parachutes and silver wheelchairs, bearhugs and white knights"--strategies adopted by company executives during takeovers.