Luck of the green? UW-Green Bay professor prefers statistical probabilities

Prof. Greg DavisHave you ever heard the saying, “you’ve got the luck of the Irish,” and believed it? Have you ever carried a lucky trinket in your pocket, say, a rabbit’s foot, four-leaf clover or special coin? Do you wear a lucky piece of clothing on the day of an exam or a presentation?

If so, perhaps you’re in the right place. Green is traditionally considered to be the luckiest color of them all, which is a good thing for all of us here at the University of Wisconsin-GREEN Bay.

At the same time, when you get the occasional unlucky parking ticket or have a rough day at school or work, can it be explained by “bad luck”? Did a black cat cross your path, did you break a mirror, or fail to knock on wood?

According to UW-Green Bay mathematics, science and statistics professor Greg Davis, “luck” is best viewed from a statistical perspective. It’s more of a mindset than anything else.

“When something happens that is unexpected,” Davis says, “you can either take the credit for it happening… accept that there is a distribution of outcomes and that you experienced a rare outcome or statistical interpretation… Or you were simply lucky one way or the other, just not realizing that statistics is a way of quantifying the experience.

“I don’t think that the expected result could be classified as bad luck as much as a bad choice.”

Statistics is the science of collecting, organizing, and interpreting data. Statistics include the plans for collecting data and the design of the experiments used and relies solely on experimentation and observation.

Davis and his faculty colleagues in math and statistics sometimes field calls from the news media when something improbable occurs. The public wants to know “what are the odds” that this event happened the way it did. Is there such a thing as good luck? Or is it always statistical probability?

The answer, replies Davis (who was lucky enough — actually, smart enough — to receive his own bachelor’s degree from UW-Green Bay in 1981) is that “luck” is mostly the result of chance. Arguably, it can also be affected by an individual’s attitudes and actions.

Superstitious beliefs and folklore are entertaining, yes. Reliable? No.

“From a statistical perspective, experiments with variability have a range of different outcomes and these outcomes often have different probabilities of occurrence. If an outcome occurs that has a very low probability of occurrence, then we can classify that outcome as being ‘lucky,’” Davis says.

“So a good question would be whether some people are luckier than others. I think that is true in the sense that some people seem to be associated with more rare events and that some people have the ‘skill’ to modify their own situation so that it appears that they are lucky.”

So, there you have it. If you’re out this St. Patrick’s Day chasing leprechauns or searching for a pot of gold, real or metaphoric, statistics indicate there’s a chance you’ll be lucky… or that you’ll be lucky to have any chance at all… but in any event…

Good luck!

– Story by UW-Green Bay student and editorial intern Daniele Frechette