Today's leadoff Monday Morning Quarterback letter comes from a Silver Spring federal worker who thinks the 5 percent pay cut proposed by President Reagan doesn't go far enough. He thinks his salary, and that of other government workers, ought to be cut 20 percent. But there is a method to his madness.

"One of the big differences between the government and the private sector," he writes, "is that federal employes . . . rebate a portion of their salary to their employer for upkeep of the employer's business.

"If federal salaries are cut 5 percent, then the employes' income tax contributions would drop about 2 to 3 percent so that in the final tally the government would save only about 2 or 3 percent overall.

"I suggest a whopping 20 percent federal pay cut and then make employes tax-exempt. This would cut paper work and give the administration an immediate spending cut of large proportion, and end the need for feds to rebate money to their employer." R.E.R.

* "I oppose cuts in pay and retirement benefits because I think they will hurt the career federal service and the people served by the government. I am not a federal worker and none of my family works for the government." M.O.W., Johnstown, Pa.

* "I would like to offer some 'reforms' to make government more like industry: Promote from within . . . stop bringing in political appointees . . . pay top salaries and let people down the line know they can aspire to reach the top . . . . Establish bonuses, stock options and savings programs . . . . Allow reasonable expense accounts . . . . Provide 'company cars' and subsidized cafeterias . . . give non-professional workers the right to strike. Finally, speak highly of your company's workers, don't abuse them." H.E.K., Arlington.

* "If Congress feels compelled to support the president's punitive changes in the retirement system . . . let it consider allowing 30-year employes the option to retire before the changes are made. This seems fair considering the diminished alternatives available to those with a 30-plus year investment in government service" who have not reached age 65. D.C.H., Arlington.

* "The flap about getting Monday off, because Inauguration Day Jan. 20 fell on a Sunday won't bother us for a while. Do you know when when that will happen again? Try Jan. 20, 2017; that is 32 years from now." Maybe we will all be retired! W.H., NAVSEA Employe.

* "The Office of Personnel Management proposal for using quit rates job turnover to determine pay raises . . . is not at all unreasonable if applied to both the military and the civil service. Military pay and allowances are becoming increasingly generous as the prevailing philosophy since the end of the draft has been to raise pay annually as a preventive measure, justified by some mythical pay comparability study engineered to give the right answers.

"The Defense establishment could hardly object to using the quit rate pay system, as the services cited this factor several years ago to stem the alarming exodus of younger pilots . . . .

"Because of the unique nature of civil service and military systems, pay comparability studies with the civilian economy will always be inconclusive or unreliable at best . . . . But OPM has proposed a new standard and in all fairness it should apply equally to the military . . . . With their built-in merit/promotion/longevity increases, annual cost-of-living raises for government personnel are a relatively recent innovation and became necessary only when the politicians began to destabilize the economy 25 or so years ago." H.L.N., Annapolis.