Despite opposition by some consumer advocates, shoppers are increasing their use of credit cards to buy groceries.
But according to research by MasterCard International and Visa U.S.A., consumers use the cards conservatively, running up less credit in supermarkets than in other types of stores.
In separate studies earlier this year, the bank card associations found that - compared to other types of sales - credit card purchases in supermarkets are twice as likely to be paid off in full when the bill comes due.
Household Diary Survey
MasterCard surveyed diaries kept by 3,000 households during the spring and summer, and found that 60% to 65% of those who charged supermarket purchases paid off their balances before interest charges accrued.
The ratio of "convenience users" to "credit revolvers" is "exactly the opposite" for other kinds of purchases, said Clark Crowdus, director of new merchant marketing for MasterCard International Inc.
In a Visa-commissioned survey of 6,000 cardholders leaving supermarkets that accept cards, 30% of card users said they paid interest to buy the groceries.
"Consumers are using the card because it's a convenient way to pay," said Peter Gustafson, a senior vice president for product and market development at Visa.
Immense Growth Potential
To be sure, grocery purchases represent only a small fraction of overall credit card use - about $2 billion out of more than $ 100 billion charged annually on Visa cards, Mr. Gustafson estimated.
But MasterCard noted that the potential for supermarket card growth is immense, given that $300 billion of groceries are bought annually in the U.S. Supermarket sales are one of the cash-dominated categories that MasterCard and Visa have identified as ripe for conversion to either credit or debit cards.
MasterCard declined to estimate its share of the market this year, but clearly expects use by grocery shoppers to increase. "Once consumers begin to use the credit card, they place 40% of their grocery expenditure" on the card, said Mr. Crowdus.
Some Observers Skeptical
The survey data, the card groups say, should dispel fears of consumer groups that supermarket acceptance makes it too easy for cardholders.to overextend or abuse their credit. "We do not see the use of Visa cards to be in any way shape or form the next step for a consumer going bankrupt or having a credit problem," Mr. Gustafson said.
However, some industry observers are skeptical about the research. "One out of two people will tell you they've never paid a dime [of interest] on their credit cards, but it's not true," said Robert McKinley, of RAM Research USA, Frederick, Md. "Three out of four do."
Mr. Gustafson said Visa verified its findings by reviewing the billing statements of the customers it interviewed.
"The fact that one third are paying interest on their groceries is something to be concerned about," said Gerri Detweiler, director of Bankcard Holders of America. "It can be a sip of serious money management or financial problems, if people are resorting to using credit cards because they can't make it though to their next paycheck."
Intensified Education Urged
Ms. Detweiler also said the percentage of people revolving their grocery expenses could rise as more markets accept the cards. She urged the card associations to step up consumer education programs.
Mr. McKinley said that banks probably will begin to monitor the level of card-charged supermarket purchases along with other warning signs, such as excessive use of cash advances. If a customer quickly ran up a bill with grocery charges, "that could be a flag," he said.
In the 18 months since Visa began pushing supermarkets to accept its cards, about 8,000 stores - represents 85% of the 50 largest chains - have joined. Visa's projected $2 billion of supermarket sales this year will be up from "nearly" "zero" in 1990, Mr. Gustafson said.
MasterCard, which stepped up its marketing to grocery stores late last year, has seen its supermarket merchant list surge from about 800 in early 1991 to 7,000 in mid-September.