Play the RBC Vampire Number Challenge!

Maia Szalavitz has a nice piece at Time showing how those Dr. Van Helsings at RAND have finally put a stake through the heart of a “vampire number”, this one being that 60% of the Mexican cartels’ revenue comes from marijuana.

(Input your best Vincent Price or Boris Karloff imitation here, with creepy organ music in background) “Vampire numbers….no one knows where they came from but they live on and on, sucking the blood out of all intelligent public policy discourse…

A 40% rise of violence against women every Superbowl Sunday and an American child’s risk of abduction by a stranger being 1 in 30,000 are among my favs. Challenge to RBCers: What is your favorite vampire number? The best answer wins 1 (one) ludicrous statistical pronouncement of your choice, to be made here by a marginally credible source, viz, me.

Author: Keith Humphreys

Keith Humphreys is the Esther Ting Memorial Professor of Psychiatry at Stanford University and an Honorary Professor of Psychiatry at Kings College London. His research, teaching and writing have focused on addictive disorders, self-help organizations (e.g., breast cancer support groups, Alcoholics Anonymous), evaluation research methods, and public policy related to health care, mental illness, veterans, drugs, crime and correctional systems. Professor Humphreys' over 300 scholarly articles, monographs and books have been cited over thirteen thousand times by scientific colleagues. He is a regular contributor to Washington Post and has also written for the New York Times, Wall Street Journal, Washington Monthly, San Francisco Chronicle, The Guardian (UK), The Telegraph (UK), Times Higher Education (UK), Crossbow (UK) and other media outlets.

31 thoughts on “Play the RBC Vampire Number Challenge!”

  1. A gun in the home is 42 times as likely to kill a household member as an intruder. (Actually, I think the source is known; it's just extraordinarily misleading.)

  2. “Vampire numbers….no one knows where they came from..¨¨ We know in this scase where the number came from, viz. a reckless 2006 estimate by the Bush administration based on 1997 data and a dud model. I invite Keith or Mark to dig deeper into the origin. The number was weird. 60% of gross revenue at an extreme pinch, but with competition in the California market from large-scale domestic production, much higher unit transport costs, and lower legal risks, it´s prima facie obvious that gross profit margins for wholesalers must always have been much lower on marijuana than for harder drugs. Were the Bushies simply reading back fallaciously fron the total street value of the respective markets?

    The popular version of Moore´s Law – computing gets twice as fast every two years – is a vampire generalisation from the narrower, and increasingly irrelevant, true version that the density of transistors on a chip doubles every two years (with related, but equally specific, laws for mass storage and optical fibre transmission). You still have to cool the chips, optimise the programs, get the data in and out, display results, integrate the whole thing reliably, etc. The strength of the chain is that of the weakest link, not the strongest. Why, the IPad boots, I´ve heard, almost as fast as a Commodore 64. There is of course very real and very impressive progress in getting computing work done, but much slower.

  3. I am hoping that the ad campaign claiming that 1 in 110 children born is autisitc is a vampire number. Otherwise, we are talking an astonishing number of autistic children are born each year. Well, that or the medical community needs to re-evaluate what it means to be autistic.

  4. I'm seconding Joshua Buhs' nomination on Eskimo words for snow. I'm a linguist by training and this drives me CRAZY.

  5. "U.S. companies spend 50 billion dollars a year training workers in basic skills like reading and math."

    I fact-checked this twenty-ish years ago as an intern at Harper's. It originally came from a survey of CEOs asking them what proportion of outlays at their companies was spent on various things. The median (or mean, doesn't matter), out-of-thin-air number from a ridiculously low response rate was 1 percent. The people doing the survey, while not taking this result at all seriously, hypothetically and for illustration multiplied that by the GNP at the time, which in the late 1980s was about $5 trillion. Cue Vlad Dracul.

  6. What Wimberly said. The interesting thing is that the number in question here came from officers of the executive branch of the US Government, speaking in their official capacity as experts on the topic. These officers simply fabricated some data, thinking that thereby they could rally support for a policy that is indefensible on its face. Apparently this is considered unexceptionable.

  7. One is the loneliest number.

    Where did that come from, and how could you even start to prove it.

    I'd say zero is even lonelier, but perhaps there is some irrational number out there with no good rational approximation, unnamed, unfindable:

    Ergo, the loneliest number must be transcendental.

  8. Lowell–

    What source do you have for the claim that we only use 10% of our brain? I've seen people try to find the origin, but with no real luck, suggesting only that it probably came out of 19th century New Thought.

  9. My vote is split between the 28 words for snow (background liknguistics) and "we use only 10% of our mental capacity" (background neuropsychology). This is usually credited to Einstein, supposedly said sometime in the thirties while at Princeton. At the time, little was known about the function of much of the brain and often extreme brain injuries would appear to have little or no effect on behavior.

  10. James Wimberley writes

    >I invite Keith or Mark to dig deeper into the origin.

    It is certainly worth digging into this on the principle of promoting accountability, although I am not sure I would know where to begin. In the year I was at ONDCP during the Obama Administration, I never heard the 60% revenue figure mentioned. The only reference I could find today to the 60% figure in any Obama-era document or speech was a brief note issued after I left which acknowledged that the number was being repeated in the media but stating that it was not reliable. That almost certainly means that whoever created the number moved on before I arrived (which would make sense if s/he were an appointee of the prior administration). A journalist with resources behind them could trawl through old speeches from the prior Administration and perhaps eventually find the first mention of the figure and the source, but that is beyond my personal abilities and available time.

  11. p.s. To Horseball, isn't the erroneous divorce statistic that half of all *people* who get married get divorced. There are about 2 million marriages and 1 million divorces a year, so there are half as many divorces as marriages. But half of all married people do not get divorced because divorced people tend to remarry and re-marriages have an even higher divorce rate than first marriages.

  12. Bless you for the link — I read this long ago (in a Language and Thought class) but hadn't seen it since. I've just circulated it to the two people I most recently heard repeat this canard and will no doubt think of others soon . . . You are a spreader of enlightenment and worthy of much praise!

  13. Dear Mr. Humphreys, I think that you're also correct, but I believe mine is still correct. This number comes from the high divorce years around 1980, when there was so-to-speak a backlog of soon-to-be-ending in divorce marriages that accumulated in low divorce years.

    A good explanation can be found here

    "A spokesperson for the U.S. National Center for Health Statistics told me that the rumor appears to have originated from a misreading of the facts. It was true, he said, if you looked at all the marriages and divorces within a single year, you'd find that there were twice as many marriages as divorces. In 1981, for example, there were 2.4 million marriages and 1.2 million divorces. At first glance, that would seem like a 50-percent divorce rate.

    Virtually none of those divorces were among the people who had married during that year, however, and the statistic failed to take into account the 54 million marriages that already existed, the majority of which would not see divorce."

  14. Damn, I've been away a bit but this looks like fun. Too bad the contest has already been won, but some of my favorite vampire numbers are about illegal immigration:

    1. "95% of warrants for murder in Los Angeles are for illegal aliens . . . " – this nugget comes from the very reliable Heather MacDonald of the equally sterling Manhattan Institute who wrote this in an Op-Ed. Where did this number come from? Her best answer, "officers."

    2. "75% of people on the most wanted list in Los Angeles are illegal aliens." – this one is pure evil. It's a vampire number that was floating around in a "report" titled "2006 INS/FBI Statistical Report on Undocumented Immigrants." The Immigration & Naturalization Service ceased in 2003 and became Immigrations Customs Enforcement and became part of Dept of Homeland Security. A vampire number from a vampire agency? Hey, vampires never die.

    3. "Nearly 35% of all inmates in California detention centers are Mexican nationals here illegally." – Vampires may look good, but they make for lousy mathematicians. This number comes from a projection from CDCR that estimated 11% of the 172,000 inmates in the California state prisons system are undocumented.

    4. "Nearly 60% of all occupants of HUD properties are illegal." – Despite Annie Kim of the LA Housing Authority shooting down this vampire fact as "urban legend" she didn't aim for the heart. Apparently, this vampire stat got its inspiration from an AP article that noted from a govt study that .4% of residents with federally funded public housing are "ineligible noncitizens." About .2% are expected to be undocumented.

  15. I've also heard another one that British bomber crews had a 0% chance of survival based on a 4% casualty rate and 25 mission tour of duty. The equation should be (.96)^25 which means a 36% survival rate. I don't believe the four percent is only fatalities, and may include any type of casualty.

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