A Morning Edition piece on the housing market blamed difficulties in the housing market in part on people being unable to get mortgages because of inaccurate appraisals. In fact, this should not on average reduce sales. While some sales will be prevented by an appraisal that wrongly comes in too low, some sales will go through that should not because an inaccurate appraisal comes in too high. Unless there is some reason there is a low side bias to the appraisals, inaccuracy by itself should not affect total sales.