What do school teachers and sumo wrestlers have in common? This is just one of the many intriguing questions that Levitt and Dubner ask in the 2005 best-seller Freakonomics. The answer: they both cheat to get ahead. Schools teachers play with their students’ grades to make them look better and have a promotion. Sumo fix fights to earn extra income while consolidating the place of their opponents in the top-tier sumo rankings.
Figure 1: Sumo is hard 
In their book, Levitt and Dubner also ask another puzzling question: why do so many drug dealers still live with their moms? They answer by showing just how poor street drug dealer are. Levitt and Dubner find that street drug dealers earn on average $3.30 an hour, much lower than even a grocery store clerk. And a lot riskier. Why do it then? Because it is an investment.
Street drug dealers are often parts of street gangs where the profits stay in the pockets of the groups’ leaders. The leaders throw parties and from time to time to share the wealth but live overall a very different life than their soldiers who sell drugs and fight to protect the drug business. Street drug dealers see the lifestyle of those at the top. They hope to get there one day. Of course, very few get to the top. Most are either killed or desist from the gang before then. But the appeal of promotions – and money – is strong. It provides a steady flow of new recruits who also hope one day to become leaders.
Figure 2: Get rich or die trying 
Today, we will pay a tribute to Levitt and Dubner and ask a similar question: do many carders still live with their moms? A carder is a criminal who steals information from credit cards. Therefore, to answer this question, we analyzed the 530,640 ads placed on the 6 largest darknet illicit markets by 13,343 vendors. We isolated the 52,986 ads related to carding posted by 1,578 and calculated their revenues based on the feedbacks they received. Our data strongly suggests that many carders probably live in their parents’ basement.
Table 1: Monthly revenues of carders
Table 1 shows that more than 50% of carders (median) don’t even earn enough in a month to buy a dollar-menu item from McDonalds. The average revenues (not profits!) sits at $807 per month. Not even enough to buy a 1 square-feet apartment, if it existed, in San Francisco. That average is pulled high by the top 1% of carders.
Table 2: Monthly revenues of top-earning carders
The top 1% of carders probably can afford a somewhat decent apartment in San Francisco with their monthly revenues of over $16,000 per month. Success is, however, not share very much. Earning $1,405 and more per month gets you into the top 10% earners of carding. At 40 hours per week, that translates to an hourly wage of $9 for carders in the top 10%. That is about 20% more than the average minimum salary in the USA but orders of magnitude more dangerous.
Figure 3: Distribution of revenues from carders
Each dot on this graph represents a vendor. This graph shows that two vendors pull in revenues of over $80,000 while most vendors barely make any revenues. Why get involved in carding then? Our guess is for those two spots. Carders can see that some of their peers generate significant sales. They probably believe that one day, that could be them as well. Just as soon as those 2 carders retire or are arrested. These 1,500 carders are playing a tournament where demand must be met by someone. What they’re hoping is that someone is them. Until then, they’ll just live with their moms.
 NPR: https://media.npr.org/assets/news/2010/06/27/sumo-c34820a96180eb40e2ea82dcf9ec47fa289e8cea-s800-c15.jpg.
 Netflix: https://scdn.nflximg.net/ipl/35734/17009a6b79f9275cef8868ecd24a4384f052002c.jpg.