Milton Friedman has a wonderful short lecture on this, about pencils no less.<p><a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=R5Gppi-O3a8" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=R5Gppi-O3a8</a>