Houses are set on the margin, but that doesn't mean the "lock in effect" doesn't have a net positive effect on prices. There is heterogeneity of sellers in how

Houses are set on the margin, but that doesn't mean the "lock in effect" doesn't have a net positive effect on prices. There is heterogeneity of sellers in how much they "must" sell (versus alternates like rent it out, not move at all if they're nearly indifferent between cities, etc). Clearly "lock in" reduces total sellers.