How much ruin can a 6-year-old possibly wreak (assuming Calvin "represents the worst-case scenario in terms of the amount of damage a child can do")? One dedicated soul has read through the comic's entire run to find out.
Reporting in the Honest and Reliable Data sub-journal of Proceedings of the Natural Institute of Science* (PNIS-HARD), researcher Matt J. Michel attempts to provide "an explicit approximation of the amount of damage that children can cause," in a half-serious effort to increase the accuracy of the U.S. Department of Agriculture's estimated cost of raising a child from birth to age 17 ($226,800–$264,600 total, for middle-classers).
To do so, Michel read through every published strip of Bill Watterson's Calvin and Hobbes in chronological order and identified every instance in which Calvin or his tiger caused physical damage. Also included were cases where explicit mention was made of Calvin having caused damage:
For every event, I recorded the date of the strip and the type of damage caused (e.g. if it was a specific item, or was property damage) with a brief description of the circumstances leading to the damage. There had to be an explicit depiction or mention of physical damage in order for the event to be recorded. Thus, any damage possibly resulting from episodes like "the noodle incident" (or its predecessor, "the salamander incident") were not counted.
The monetary cost of damages is only mentioned on a handful of occasions in the course of the strip, so Amazon was consulted in estimating the cost of damaged goods. homewyse.com and fixr.com were referenced in estimating cost for property damage. The result of Michel's analysis is the chart you see at the top of this post, from which he concludes that Calvin caused an estimated $15,955.58 worth of damage, or $1,850.55 annually.
Michel has since updated the paper with an errata article, which reads as follows:
For the article, "How much damage can a 6 year-old possibly do? An analysis of the cost of raising a child like Calvin from Calvin and Hobbes," by Matt J. Michel, which appeared in Volume 1, September 12, 2014, of Proceedings of the Natural Institute of Science-SOFD (Volume 1, Paper 1; first published September 12, 2014, and available online here), reddit user zeinshver pointed out that the estimation of $50 to replace a coffee table into which Calvin had hammered eight nails (click here for comic) lacked an estimation of the cost needed to replace the eight aforementioned nails. The author concedes this point and apologizes for the mistake. On page 2, the first sentence of the "Results and Discussion" section should read, "In total, Calvin caused an estimated $15,955.58 worth of damage..." and not "In total, Calvin caused an estimated $15,955.50" worth of damage...." The author also notes that the entry for "December" in Table 1 should read "672.58" and not "672.50." In addition, the author notes that Figure 1 should be changed but that the author is too lazy to make a new graph.
He has also published an errata for the errata.
We commend Michel for his considerable efforts, and look forward to any future research published either by him or his esteemed journal (of which, we might have failed to mention, he is the Editor).
*According to its About/FAQ section, PNIS is:
a part-serious, part-satirical journal publishing science-related articles. There are three types of PNIS articles: SOFD [Satirical or Fake Data], HARD [Honest and Reliable Data], and Editorial... HARD is the serious PNIS sub-journal. Papers published in HARD use actual data that were collected in some way by the authors (for example, data collected from an Internet resource (and properly cited, of course), or data from an experiment conducted by the authors).