WHY MY STATISTICS ARE MORE ACURATE than either those from the Multiple Listing Service or the Los Angeles County Tax Records (used for the Los Angeles Times reports) ... First of all, I must state, no sources are absolutely perfectly accurate (even mine) !!! However, by merging the data from both of the sources, the resulting data is much more accurate. The accuracy of any statistics is solely dependent upon the accuracy input data.
The MLS inaccuracies are, for the most part, a result of agent input errors ... wrong property type, inaccurate sale date, wrong MLS-defined area, missing square footage, and duplicate MLS entries. The County Records (obtained from DataQuick®, a paid service) often do not report the sales price and, therefore, those sales are not included in their stats. Additionally, there are a number of properties that sell without a Realtor® which are discovered in DataQuick®; but do not show in the MLS stats.