Morning Must-Read: Carter Price: Piketty’s Data Deserve Better Analysis

Carter Price: Piketty’s data deserve better analysis: “Perhaps the key claim by Giles is erroneous.

Giles bases his argument that there was not an increase in wealth concentration in the United Kingdom but rather a decrease on a single data point from a 2010 wealth survey in the UK. Because that survey did not exist in 2000, it cannot be directly compared to other time series data without harmonization. The entirety of the drop Giles claims is occurring can be explained by switching from one survey to another…. Piketty had to look at disparate data sources, harmonize them (so that he could compare apples to apples), and draw conclusions. Wealth is notoriously difficult to measure, which makes working with wealth data especially tricky. Piketty has been exceptionally transparent with the data sets…. Giles uses the raw, non-harmonized wealth data to claim that wealth inequality in the United States has been flat and that it has been decreasing in the United Kingdom. Yet by combining these non-harmonized data sets, Giles is comparing apples to oranges…