Abstract
Although real estate valuation is supposed to make the market transparent, it has been noted to be partial in many countries. Analysis of literature and results of the statistical analysis of survey responses of Polish property appraisers indicated that: Property valuers operate in an environment which exerts influence on the final result of valuation. The attempts of the client to influence the valuation process and their effectiveness do not depend on the gender and age of the property appraiser. The problem of valuation bias should be seen in the weakness of the system enforcing compliance with ethical standards, with this being an area which requires reinforcement in many countries.