Counting the Consequences

Number crunching reveals the surprising ways laws work
By Matt Windsor • Illustration by Ron Gamble • Photo by Nik Layman
Illustration of Justice with numbers and charts
Number crunching reveals the surprising ways laws work
By Matt Windsor • Illustration by Ron Gamble • Photo by Nik Layman


Griffin Edwards, Ph.D., entered college “figuring out if I should be a lawyer or an economist.” He ended up combining the two. Edwards, an assistant professor of economics in the UAB Collat School of Business, specializes in empirical legal studies, a young discipline that applies high-powered statistical methods to lawmaking. By calculating and comparing everything from murder rates to crop yields, he reveals the unintended consequences of legislation.

To Warn or Not to Warn

For decades, mental health professionals have chafed against so-called “duty to warn” laws, which require them to notify authorities if their clients threaten others or themselves. These laws originate in a California Supreme Court decision; the case concerned a woman murdered in 1969 by an unbalanced graduate student who had previously confessed his intentions to his psychologist. Since then, 43 states have passed “duty to warn” laws. Some require mental health professionals to warn authorities or the threatened party; others say professionals can warn at their discretion.

Mental health professionals claim that such laws make it less likely that potential victims will be protected, Edwards says. “They argue that the whole reason the doctor-patient relationship works is that everything said is confidential,” and that the laws mean patients will be less likely to divulge violent plans—leading to fewer opportunities for intervention through counseling.

Determining an answer is not obvious. How can you tally the number of people prevented from murder, or suicide, by a psychologist’s warning? The goal of the law, after all, is to stop these events from happening.
Photo of Griffin EdwardsGriffin Edwards

Murder Mystery

Edwards developed a solution: If mental health professionals were right, suicides and murders should increase in states after these laws are passed. But he had to tease out this signal from a sea of other possible contributing factors. For example, suicide rates may be higher in the Pacific Northwest due to gloomy weather and a plentiful supply of isolated bridges, Edwards notes.

Murder rates fluctuate as a factor of policing strategies, drug violence, and a host of other reasons. So Edwards compared statistics from states after they passed duty to warn laws to data from the same states prior to passing the laws. Then he compared that difference to numbers from a state that had never passed the laws.

What happened? “The psychologists are right,”  Edwards says. In a 2013 paper, “I found that these laws actually increase suicides among teens, but have no effect on adult suicides,” he notes. In a separate paper, Edwards found that “homicides increase by anywhere from 5 to 7 percent” after mandatory duty to warn laws are passed. “Permissive” laws, which say mental health professionals can warn potential victims or the police, had no statistically significant effect. Edwards is now examining involuntary commitment laws. “Every state has a different length of time you can commit someone involuntarily if you suspect they are a danger to themselves or others,” ranging from three days to three years, he explains. Now Edwards wants “to see if locking someone up actually stops the crime from happening or just delays it.”

Grain and Greens

Edwards’s interests range beyond mental health. “Economics is the study of everything,” he says. He has used government data on hops and barley crops to estimate how much people drank during Prohibition (not as much as you may think), and pored over medical records to determine how that era’s alcohol ban affected infant health (it was good for babies).

One of Edwards’s new papers answers a question that caused controversy in the sports world in the early 2000s. Casey Martin, a talented golfer with a degenerative knee condition, won a Supreme Court case against the Professional Golf Association (PGA), which wouldn’t let him use a cart to move around the course in its mandatory Qualifying School. The justices ruled that the Americans with Disabilities Act applies at Pebble Beach and Augusta National as well as any other public place.

The PGA had argued that walking was crucial to golf. But, Edwards wondered, how much of an advantage did Martin get from his cart? He hit on a quirk of NCAA scheduling for college golf tournaments. Because these events fit into a weekend, all players use carts one day and walk the other day. Analyzing hundreds of tournaments, Edwards found that players scored worse when they drove carts—possibly because the trudge to the next tee helps a player burn off steam from a bad shot and offers a chance to visualize the approach for the upcoming hole, Edwards speculates.

Instead of giving Martin an unfair advantage, driving “actually puts him at a disadvantage,” Edwards says. “The point of that paper is, maybe we could be more accommodating to people with disabilities.”

Judges are beginning to cite empirical legal studies research in their opinions, Edwards says—a trend that should continue as the discipline matures. But Edwards has another motivating factor: “I try to do research that’s not totally boring to my wife.”

This story originally appeared on The Mix, UAB's research blog.

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