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Overcoming Bias Commenter's avatar

@KhothI was a little bit too fast with my praise of the eeckhout paper (cities).

If you take a closer look at the whole thing, there are more than 20 % of the population missing in the plot. Most (european) countries do not accept "cities" with less than 2 - 5000 people, cutting off the left 2/3 of the data points, or half the ln size distribution. On the right side, as the paper states, he takes the smaller US size definition, putting LA at 3.7 Mio, instead of 16 Mio with the definition closer to european views, and strong deviation from a log normal or Zipf distribution. That leaves than the transition region for fitting, and you can do this in many ways. You can even find on the homepage of the author some comment exchange in 2009 with Levy on this. Beyond that, if you look up data on "urbanization", (e.g. CIA, wiki) you will find that over 50 % of the differences are due to different definitions of "city" (see German wiki "Stadt": DK: 200; JP 50 000)

bottomline: if you want, you can fit the log normal distribution, but many others as well, and it doesn't prove anything about underlying mechanisms.Very typical results for economics / sociology.

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Overcoming Bias Commenter's avatar

Hah, I thought the firm size graph looked suspiciously neat. I hadn't noticed that the scale on the y-axis was impossible. Nice catch.

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