> As of the fourth quarter of 2020, the U.S. had a housing supply deficit of 3.8 million units. These 3.8 million units are needed to not only meet the demand from the growing number of households but also to maintain a target vacancy rate of 13%. Between 2018 and 2020, the housing stock deficit increased by approximately 52% (See Appendix 1 for detailed calculations of the Housing Supply Deficit).