&quot;High cost of living&quot; is a concept you get to use in personal decisionmaking, but it&#x27;s not a concept you get to use in probing this causation, because it becomes tautological.<p>High cost of living, where cost of living is mostly housing, is associated with high economic productivity combined with low housing stock.  It cannot be used to <i>normalize</i> high salaries to some other abstract concept that says useful things about economic productivity, because it only co-occurs with high salaries.<p>The article is asking why city A and city B became differently economically productive, not for excuses as to why one isn&#x27;t <i>technically</i> rich or comparisons of disposable income.  That&#x27;s a different discussion.