Something that decreases the willingness of sellers to sell will increase the price. That is basic supply and demand. If a retired couple downsizes from a thre

Something that decreases the willingness of sellers to sell will increase the price. That is basic supply and demand. If a retired couple downsizes from a three bedroom house to a one bedroom apartment because their kids have grown up, that frees up housing for someone else to use. Prop 13 discourages them from doing that because the property taxes on a one bedroom apartment at a 2018 assessment can easily be many times higher than the property taxes on a three bedroom house at a 1970 assessment+2%/year.