I think his assumptions are in error When ever you have a large group of results the larger the sample size the more accurate the trend. In this case there are a results that haven't been reported, yet the existing sample size of results is way larger than required. It is enough to establish a trend. This allow the results to be reported on the assumption that the same trend is happening through the market. On the other hand if you take Hiesa assumption which is all results not reported were non sales I think that would be very short sited, as well as throwing out basic scientific sampling and extrapolation of results. But then again not sure if Hiesa is aware of statistical analysis or extrapolation of sample data trends? Either way I am not a realestate agent, but have been involved in the property market 30 + years
