Mr. Carter's opponents mounted a rhetorically brilliant attack on his proposal, arguing that because consumers would get back every cent they paid in gasoline taxes, they could, and would, buy just as much gasoline as before. Many found this argument compelling, and in the end, President Carter's proposal won just 35 votes in the House of Representatives.

The experience appears to have left an indelible imprint on political decision makers. To this day, many seem persuaded that tax-cum-rebate proposals do not make economic sense. But it is the argument advanced by Mr. Carter's critics that makes no sense. It betrays a fundamental misunderstanding of how such a program would alter people's opportunities and incentives.

Some examples help to illustrate how the program would work. On average, a family of four currently consumes almost 2,000 gallons of gasoline annually. If all families continued to consume gasoline at the same rate after the imposition of a $2-a-gallon gasoline tax, the average family would pay $4,000 in additional gasoline taxes annually. A representative family with two earners would then receive an annual payroll tax refund of $4,000. So, if all other families continued to buy as much gasoline as before, then, this family's tax rebate would enable it to do so as well, just as Mr. Carter's critics claimed.

But that is not how things would play out. Suppose, for example, that the family was about to replace its aging Ford Explorer, which gets 15 miles per gallon. It could buy another Explorer. Or it could buy Ford's new Focus wagon, which has almost as much cargo capacity and gets more than 30 miles per gallon. The latter choice would save a whopping $2,000 annually at the pump. Not all families would switch, of course, but many would.

From the experience of the 1970's, we know that consumers respond to higher gasoline prices not just by buying more efficient cars, but also by taking fewer trips, forming carpools and moving closer to work. If families overall bought half as much gasoline as before, the rebate would be not $2,000 per earner, but only $1,000. In that case, our representative two-earner family could not buy just as much gasoline as before unless it spent $2,000 less on everything else. So, contrary to Mr. Carter's critics, the tax-cum-rebate program would profoundly alter not only our incentives but also our opportunities.