February 29, 2012

Recycled bad statistics

In a report on a cannabis-growing operation in Hamilton, the Herald gives us both new dodgy numbers and recycled dodgy numbers.

The new numbers (from the police)

  • Between 50 and 100 plants
  • a mature plant worth about $1000
  • If 100 plants were allowed to grow to maturity, conservatively worth $400000 in income.

Simple arithmetical operations on these numbers show them to be not entirely consistent: if you can turn a crop that will at maturity be worth between $50,000 and $100,000 into $400,000 in income, you’re in the wrong business.

The recycled numbers are

A study involving the police and Environmental Science and Research released last month found that levels of THC, the primary psychoactive compound in cannabis, was more than four times stronger than in 1996 when ESR last tested it.

As we pointed out last time this statistic appeared, and will keep pointing out when it gets recycled in the future, what they actually found was that in 2004-2006 the maximum concentration was four times higher than the mean concentration in 1996.

 

 

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar

    “what they actually found was that in 2004-2006 the maximum concentration was four times higher than the mean concentration in 1996”.

    Wow. Even by the standards of this blog, that’s amazingly misleading reporting.

    12 years ago

  • avatar
    Luke D

    Keep up the good work. It’s a travesty to see this misinformation (and the numerous other examples you have blogged about) perpetuated in our self described ‘leading’ newspaper.

    12 years ago