The theory is that by correcting for autocorrelation, you are uncovering a "true" return from a series of observed returns that contain illiquidity or manual pricing effects.
Return.Geltner(Ra, ...)
where $
Geltner, David, 1991, Smoothing in Appraisal-Based Returns, Journal of Real Estate Finance and Economics, Vol.4, p.327-345.
Geltner, David, 1993, Estimating Market Values from Appraised Values without Assuming an Efficient Market, Journal of Real Estate Research, Vol.8, p.325-345.
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