Here is some critical comments about the universal nature of power laws in science (in Science): <a href="http:&#x2F;&#x2F;science.sciencemag.org&#x2F;content&#x2F;335&#x2F;6069&#x2F;665.full" rel="nofollow">http:&#x2F;&#x2F;science.sciencemag.org&#x2F;content&#x2F;335&#x2F;6069&#x2F;665.full</a>