Penny defenders argue that the coin is the only thing standing between the U.S. and a devastating inflationary spiral, since rounding would always mean rounding up. Whaples did a study of 200,000 transactions at a multistate convenience-store chain and found that prices would be rounded down about as often as they would be rounded up. Finland ended production of its 1-cent and 2-cent euro coins with no dire consequences. U.S. military bases overseas stopped using pennies in the 1980s, adopting a rounding system for cash transactions that has been operating perfectly smoothly.
The main force behind keeping the penny is pure numismatic nostalgia. There is no doubt that the penny is an endearing and very American coin. Generally, I sympathize with the sort of cussed traditionalism that has resisted the introduction of the metric system and the one-dollar coin. But these innovations also represented a significant nuisance factor, in the effort it would take to learn a new measuring system and to distinguish dollar coins from quarters. In the case of the penny, it is the traditional rather than the innovation that is the nuisance.
People should be free to be nostalgic about the penny, but not to make everyone else endure it. As the penny slowly fades away, they can keep bucketfuls of them in their houses to remind them of whatever it is they want to be reminded of. The rest of us, meanwhile, can get on with life with pockets and purses full of coins worth the bother.