The data on economic inequality is now extensive and largely consistent: wealth and income have concentrated significantly in most developed economies over the past half-century, and the mechanisms — tax policy, labor market deregulation, the returns to capital — are reasonably well understood. The debate is not primarily about whether inequality has grown but about what, if anything, that growth demands. Reason holds that the factual question and the normative question should be kept separate.
Each step builds on the last.