In Tuesday's column, I called attention to an eye-opening article about income taxes that Paul Craig Roberts wrote for the March issue of Harper's.

Afterward Roberts phoned to thank me for mentioning his article. "Well, thank you, " I said. "Usually people don't call except to complain about mistakes."

There was silence for a moment. Then, with hesitation, Roberts said, "Well, there was one small mistake."

"What did I do?" I asked.

"You got my name right the first time - Roberts," was the reply. "But thereafter your typesetter changed me to Richards each time you referred to me."

I apologized and told him the careless typesetter's error left me mortified. I didn't have the heart to explain that for many months I have, in effect, been the typesetter for this column.

I "keyboard" the column into a video display terminal instead of a typewriter. Later, after several of us have revised, copyread and proofread the piece repeatedly, another man hits three keys: the s, the e, (together they become the abbreviation for the command, "Set") and the "send line" key. This causes the final revision of what I have keyboarded to be automatically set into "cold type" - a photographic process that involves paper, not "hot metal."

It takes at least one full hour of fumbling and complaining for a typewriter jockey to learn to use a VDT insteed, but once that hour is finished, most of us love the VDT. I don't ever want to go back to typewriters. The VDT is much quicker and easier to use, and much more versatile.

There's only one thing wrong with it. When a typographical error slips through, there's nobody to blame it on except yourself. Switching names in mid-story is the kind of goof a cub reporter learns to guard against. The embarrassment of a journeyman who makes that blunder is beyond description - even with the aid of the versatile VDT.