Having kids is expensive. Just ask Calvin’s parents from the comic strip Calvin And Hobbes. Matt J. Michel, who edits the humorous scholarly journal Proceedings Of The Natural Institute Of Science (PNIS, for short), surveyed every Calvin strip from 1985 to 1995 in an attempt to estimate just how much property damage Calvin and his tiger buddy Hobbes did over the course of 10 zany years. Michel’s research determined that Calvin did about $15,950.50 worth of damage during his run—not accounting for reverse inflation, of course. (To Michel’s credit, he did estimate property damage using the zip code for creator Bill Watterson’s residence in Chagrin Falls, Ohio, thus taking regional labor and materials costs into account.) That works out to about $1,850.55 per year, not including the two times Watterson took a sabbatical from the strip. Michel’s research documents a number of costly infractions, from that time that Calvin broke a $2 jar to the five different times he flooded parts of his house at an estimated cost of about $4,798.83 per event. What a scamp.