1. Survivorship bias. The ones who don&#x27;t do well are more likely to be dead (edit: or to have left) and aren&#x27;t counted in your average.<p>2. Self-selection bias. The ones who import themselves are not a random sample, they move because they see an advantage for themselves.<p>3. From your link: &quot;Furthermore, this was achieved mostly by just one group, essentially an extended family, the Patels&quot; and &quot;Traditionally, most of the finance to start a business comes from within the family, or at least the community.&quot; Most poor people do not have such good connections or ability to borrow money.