Distributions of GDP across versions of the Penn World Tables: A functional data analysis approach

Data in the Penn World Tables (PWT) have been subject to a series of revisions since its first release in the early 1990s, and the amendments are substantial for many countries. This paper uses functional data analysis to examine the distribution functions of GDP across different versions of the PWT. We find no support for distribution equality hypothesis, indicating that GDP in different versions do not share a common underlying distribution. This suggests, at the least, a need to use caution in drawing conclusions from a particular PWT version, and conduct appropriate sensitivity analysis to check the robustness of results.