Editing Price index (section)

==== CSWD index ====
Named for Carruthers, Sellwood, Ward, and Dalén, a geometric mean of Carli and harmonic indices:<ref>PPI manual, 597.</ref><ref>Export and Import manual, Chapter 20, p. 8</ref>

: <math>P_{CSWD} = \sqrt{P_{C} \cdot P_{HR}}</math>

In 1922 Fisher wrote that this and the Jevons were the two best unweighted indexes based on Fisher’s test approach to index number theory, balancing Carli’s bias with harmonic stability, though it lacks economic weighting.<ref>PPI manual, 597.</ref>