Vacant properties have a lot of negative externalities -- higher safety risks, reduction in the quality of a neighborhood and in foot traffic (harming other bus

Vacant properties have a lot of negative externalities -- higher safety risks, reduction in the quality of a neighborhood and in foot traffic (harming other businesses), higher incidences of squatting/homeless encampments, etc. A vacancy tax is an attempt to correct for those externalities and encourage better behavior from landlords. This is a situation where just having something is noticeably better than nothing at all.