Mortarboard formula explained!

We in University Communications think we’re pretty good at understanding the messages graduates write on their caps, but this one stumped us. We reached out to the Math Department, whose faculty offered some theories (tensors?) and then suggested it might come from actuarial science: the study of the liabilities and risks a company faces when it offers an insurance product or pension plan. Could the P stand for premium, as in life insurance?

Faculty associate Kirk Peter gave us the answer: “The p here isn’t actually premium but the probability of survival. The 4 and 18 subscripts represent the probability of an 18 year old surviving 4 years. The tau in the superscript represents surviving from all causes.

“Very clever. The 1 represents 100 percent probability of survival. Of course that is with perfect looking backward information.”

Cheers to L Lindblom, who made this cap, and all the other actuarial science majors graduating this weekend!