Purdue Business & Finance Briefs

February 1997

Effectiveness of warnings may depend on user, expert says

WEST LAFAYETTE, Ind. -- Why don't people heed warnings on products such as alcohol, glue and cigarettes? The answer has to do with how people weigh benefits vs. risks when making a decision, says a Purdue University expert on warning label design.

"If someone perceives a benefit in not following a certain safety rule or warning, they are likely to violate the rule or disregard the warning," says Mark Lehto, associate professor of industrial engineering.

In one study, Lehto found only one out of 54 subjects heeded the warning on a glue label to ventilate the room while using the product, despite the glue's foul odor.

"This study suggests that if someone's main goal is to complete a task, the benefits he perceives in finishing may outweigh the risks of skipping a safety step," Lehto explains. "Similarly, if someone's out to have a good time, the benefits he sees in having fun may outweigh the risks he sees in driving drunk. If you want people to behave more safely, you need something more dramatic than a warning label."

Increasing numbers of product liability lawsuits point to a need for improved criteria for deciding when and how to provide warnings, Lehto says. He has spent much of his career developing national and international guidelines for making warnings more effective.

For example, Lehto says responsible-drinking ad campaigns might be more effective if they emphasized the benefits of not drinking and characterized nondrinkers as more attractive or cooler than drinkers.

Products that emit warnings, such as smoke detectors, also could be made more effective if they took advantage of individual preferences, Lehto says. He is looking into a relatively new concept -- adaptive warning systems -- that may better meet the individual behavior patterns of a user.

"If a warning system such as a smoke detector is too sensitive, it will almost always detect a problem -- but it will also give off a lot of false alarms," Lehto explains. "After a while, some people won't pay attention to it any more and might react by turning it off completely, which isn't safe." With an adaptive smoke detector, individuals could adjust the device to be very sensitive or not-so-sensitive, depending on their preferences and lifestyles, he says.

Lehto and his colleague Jason Papastavrou, assistant professor of industrial engineering, are conducting experiments to determine whether people can adjust an adaptive warning system to their own behavior and sensitivity without jeopardizing safety.

CONTACT: Lehto, (765) 494-5428; e-mail, lehto@ecn.purdue.edu

Research may help workers avoid carpal tunnel syndrome

NOTE TO JOURNALISTS: An abstract of the Purdue study is available from Amanda Siegfried, Purdue News Service, (765) 494-4709.

WEST LAFAYETTE, Ind. -- Purdue University researchers are lending a helping hand to the thousands of people who may be at risk of developing carpal tunnel syndrome.

In a recent study, researchers developed a model that can predict the odds of an individual acquiring carpal tunnel syndrome, a cumulative disorder of the hand and wrist and one of the most common disabling injuries in people who use computer keyboards.

The model is based on more than 60 factors, including the time spent working at a keyboard, posture, wrist position and wrist size. "It's similar to giving someone a cholesterol screening test and being able to determine how much at risk that person is for heart disease," says Gavriel Salvendy, the NEC Professor of Industrial Engineering. His former graduate student, Aura Matias, collected the data and developed the model for her doctoral dissertation. She now resides in the Philippines.

"Other assessment models typically describe a person's condition, often after they have already acquired carpal tunnel syndrome or are beyond treatment," Salvendy says. "This model can be used to assess people's risk before they acquire the problem."

According to the Purdue study, the risk factor contributing most to developing carpal tunnel syndrome is the amount of time spent using the keyboard, Salvendy says. "We knew that increased duration was bad, but we didn't know quantitatively how much damage is done," he says.

For example, increasing the duration of keyboard work from 15 minutes a day to four hours a day increases a person's probability of acquiring the syndrome from about 30 percent to more than 90 percent. Factors such as the length of an individual's arms, age, height and weight contributed least to the development of the syndrome. Other contributing risk factors include:

"Now that we know these risk factors, we can tell people what needs to be changed to reduce the likelihood of their getting carpal tunnel syndrome," Salvendy says. For example, to reduce the duration factor, Salvendy suggests that office workers rotate between jobs such as typing and copying.

Matias' model was based on a study of 100 female office workers who used computer keyboards without a mouse. Forty-five subjects had medically documented cases of carpal tunnel syndrome, while 55 did not.

CONTACT: Salvendy, (765) 494-5426; e-mail, salvendy@ecn.purdue.edu

Internet sales won't doom retail stores, expert says

WEST LAFAYETTE, Ind. -- Despite what some experts are predicting, shopping on the Internet does not mean the demise of malls and retail outlets, says a Purdue University expert.

"We've heard people crying wolf before," says Richard A. Feinberg, director of Purdue's Retail Institute and head of the Department of Consumer Sciences and Retailing. "When the home shopping networks first appeared on television, experts started telling us that consumers would eventually do all of their shopping at home by phone. What these purveyors of doom fail to realize is that a tremendous number of individuals truly enjoy the shopping experience. They love to see, feel, smell and try out merchandise before they buy."

Feinberg acknowledges that television shopping channels and Internet shopping have taken a bite out of on-site outlets' profits, but he says the bite hardly draws blood.

"Estimates show that retail sales on the Internet will grow from $500 million in 1996 to approximately $7 billion in 2000," he says. "Those figures sound impressive until you compare them to the $2.3 trillion in retail sales and $70 billion in catalog sales in 1996."

That's not to say doing business on the Web isn't a good idea for retailers, Feinberg says.

"The Internet is a profitable outlet for a few select types of businesses," he says. "Candy, coffee and flowers appear to be doing well."

Before retailers go on-line, Feinberg says, they need to take a close look at their customers and their services. By encouraging local customers to shop on your Web site, you may be discouraging them from visiting your store. That's not good, since a large percentage of retail sales are "impulse" sales, Feinberg says. However, if you have a product that appeals to people 3,000 miles away, the Internet can be a great way to reach them, he says.

"If your customers and services are unique and fairly narrow in scope, there's a much better chance your product will be discovered and sell well on the Internet," he says. "But, you have to remember that Internet shopping is nothing more than an electronic catalog and that returns will kill you, as they do with regular catalog sales. Returns are a tremendous headache in an electronic medium."

Feinberg also warns of Internet "thieves" who charge thousands of dollars for spots in virtual malls.

"The National Retail Federation will help you set up a Web page for $199," he says. "But don't be fooled into thinking you're going to get rich selling on the Internet. People love to shop in stores. It's as American as baseball and apple pie -- and to get those, it's still quicker to jump in the car."

CONTACT: Feinberg, (765) 494-8296; e-mail, xdj1@vm.cc.purdue.edu.

Prof: Inflation adjustment means de facto tax increase

WEST LAFAYETTE, Ind. -- Claiming that the U.S. Consumer Price Index overstates inflation, a government panel recently recommended a change in the way the index is calculated.

A Purdue University economics expert said the proposed change amounts to little more than a de facto tax increase for all Americans, and is politically, rather than economically, motivated.

"If the index is recalculated as the panel would have us do, it will appear as if real incomes are rising faster," said Jon D. Haveman, assistant professor of economics. "It also will push millions of Americans into a higher tax bracket. And cost-of-living increases and benefits to Social Security recipients, veterans and government retirees will rise less quickly. The government gets an increase in revenues and a decrease in expenditures, both of which reduce the deficit."

The Consumer Price Index, issued monthly by the Bureau of Labor Statistics, is a comparative analysis of the changes in prices of retail goods and services. According to the index, inflation runs about 3 percent annually. The government uses the computations to index government payments, measure the overall standard of living, and index tax brackets.

Advocates of the adjustment say the current calculation overstates inflation by more than 1 percentage point because it doesn't take into account consumers who buy at discounted prices. The panel, headed by Michael Boskin, claims the adjustment could reduce the federal deficit by as much as a trillion dollars over the next 10 years.

Haveman said inflation may well be overstated, but not by that much.

"The panel appears to be aggressively downgrading the rate of inflation as a way of reducing the deficit, which it does," he said. "Who would say they are against reducing the deficit, especially if it can be done by simply jiggling a few numbers? What they aren't telling us is what it's going to cost us."

Americans living on fixed incomes will be hit the hardest, Haveman said.

"There are somewhere in the neighborhood of 60 million people living on fixed incomes in this country," he said. "Every one of them has income adjusted by the rate of inflation as calculated by the CPI."

CONTACT: Haveman, (765) 494-6156; e-mail, havemanj@mgmt.purdue.edu

Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu

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