IRR and Quartile "Distortions"

What is the best way to measure performance of the private equity asset class? An age old debate, IRR - internal rate of return - has been the traditional way to track and benchmark private equity returns relative to other investments. But IRR fails to tell the entire story. Professor Oliver Gottschalg, a leading academic on private equity performance, discusses how the standard math of an IRR calculation can distort a track record as either unfairly positive or negative.