TY - RPRT AU - Brown, Jessica H. TI - Undersupply or Lack of Demand? Evaluating Measures of Child Care Access PY - 2026/Apr/ PB - Institute of Labor Economics (IZA) CY - Bonn T2 - IZA Discussion Paper IS - 18597 UR - https://www.iza.org/publications/dp18597 AB - The most widely used measure of child care access is “child care deserts,” defined as areas with three or more young children per licensed child care slot. But a high child-to-slot ratio may reflect low demand for formal care rather than a shortage. In the canonical model, equilibrium quantities reflect local demand and costs, so the ease of finding care should not vary systematically. I use center-based provider vacancy rates as a proxy for families’ ability to access care and test whether they are negatively correlated with desert status and two alternative measures that adjust for demand. The first captures deviations between actual and predicted supply in demographically similar areas. The second compares licensed slots to the number of young children with all parents working. Desert status weakly predicts low center-based vacancy rates, while the alternative measures strongly predict low infant and toddler vacancy rates. These findings suggest that child care is harder to find in some areas, providing suggestive evidence of market frictions and a potential role for policy. However, identifying such areas requires adjusting low supply thresholds for local population characteristics. KW - child care market KW - child care deserts KW - targeting ER -