Shortly after publication of the Jan. 6 column, I received a letter from Robert J. Meyers disagreeing with my opinion that the Social Security offset for some recipients of civil service benefits is an inequity. Mr. Myers wrote: "I must disagree with your answer to the question about the 'spouse government pension offset' under Social Security.

"This is not an inequity! Rather, it provides equitable and consistent treatment in comparison with a couple both of whom are in covered employment under Social Security. In the latter case, each member of the couple can, in essence, receive only the larger of their own benefit or that from their spouse's earnings record. So too, where one spouse is under CSR (and not SS), it does not seem at all unfair that both the CSR benefit and an SS benefit from the other spouse are not paid in full."

Mr. Myers has pretty impressive credentials: He was chief actuary of the Social Security Administration from 1947 to 1970 and deputy commissioner of the SSA in 1981 and 1982. During 1982 and 1983, he served as executive director of the National Committee on Social Security Reform.

However, I remain unconvinced by his argument. I think the case he cites for comparison demonstrates another inequity. The case of the two-earner couple -- each of whom is limited to either his or her own benefits or the amount based on the spouse's earnings record -- can itself be compared unfavorably.

Consider a single-worker couple at retirement. The worker -- the husband in the traditional family -- collects benefits based on his earnings record. The wife also collects, based on the husband's record. But in the two-earner family in which, let's say, the wife's own benefit is lower than she could receive on her husband's record, she will naturally opt for benefits on his record.

Now she is receiving exactly the same monthly benefit as the wife who never worked outside the home. I am not denigrating the homemaker's contribution to the family welfare and, in fact, to its earnings; but I am unhappy with the idea that the wife who was employed outside the home paid Social Security taxes while she worked and now, in effect, gets nothing in return.

If you agree with my reasoning that this represents an inequity, then I must go one step further to say that comparing one system's inequity with another system's inequity may demonstrate consistency but really doesn't prove that either one is, in fact, fair. Sorry, Mr. Myers -- I stand by my original belief that the civil service offset is an inequity and that it is but one of several inequities in the Social Security system.

Q. In 1985, I purchased some municipal bonds; at the time of purchase I paid the broker for the interest earned when the bonds were owned by someone else. Now I have received a Form 1099 showing that I received six months' interest instead of the three months during which I was the actual owner. When preparing the worksheet to determine what part of my Social Security benefits is taxable, which figure do I use -- the total on the 1099 or the difference between that total and what I paid the broker at the time of purchase?

A. The answer is easier than the question: The amount of tax-exempt interest to be used in computing the tax status of your Social Security benefits is the net amount actually received by you; that is, the gross amount on the 1099 minus the amount you prepaid to the broker.

Q. In your income tax guide that appeared in The Post on Feb. 10, you said under "Contributions" that, instead of the standard rate for use of a car for charitable purposes, the actual out-of-pocket costs may be claimed, including "fuel and maintenance, but not depreciation or insurance." The IRS informs me that maintenance costs are not deductible. Would you clarify this?

A. It's easy to clarify -- I goofed. The word "maintenance" got in there inadvertently. When using your personal vehicle for charitable purposes, you may claim either the standard rate of 12 cents a mile or the actual operating costs such as fuel, oil, tolls and parking fees, but not depreciation, maintenance or repairs. Sorry -- I hope this error didn't create problems.