Calculating the real return on a sovereign wealth fund

摘要

We present a new methodology for calculating the real return on sovereign wealth funds (SWF) that share the investment objective of maximizing international purchasing power in terms of goods and services. Specifically, we modify the traditional approach for deflating the nominal return along three dimensions: the aggregator formula, the measure of international prices and the weighting scheme. We argue that a geometric average of price levels is an appropriate aggregator formula for capturing the deflationary effects of imports increasingly originating from low-cost countries, and that import prices paid by the SWF owner and weights reflecting the owner's import pattern are consistent with the investment objective. Our proposed approach, using the Norwegian Government Pension Fund Global as an illustration, raises the estimated average annual real rate of return over the sample period of 1998-2012 from 3.1% to 4.9%.