According to a REALTOR.com study, housing inventories dropped 12% nationally from 2018 to 2019, the largest year over year decline in nearly 3 years. As a result, the U.S. market has a large housing inventory under supply. This is occurring just as 4.8 million millennials are reaching 30 years of age, an age where previous generations have bought homes. Arizona is not immune to the shortage, as according to the study the fifth biggest decline in active listings (-29%) occurred in the Phoenix-Mesa-Scottsdale metro area.