Table C1 presents the predicted relation between union membership and covariates at teacher-, school-, and district-level only for districts that are covered by CB contracts. Panel A shows the results for the CBRTW states and panel B for the Agency states. To a large extent these results for those teachers covered by a CB agreement replicate the patterns observed in Table 4. In both CBRTW and Agency states, teachers are more likely to unionize if their school climate is less favorable and their schools suffer from more problems. In Agency states, teacher morale is an additional predictor of union joining. In both CBRTW and Agency states, Hispanic, male, part-time, alternatively certified, charter school, and Southern teachers are less likely to join unions. Experienced, elementary school, special education teachers, and teachers with master's degrees and education specialist are more likely to be union members, regardless of legal regime when covered by a CB agreement. Overall, the magnitudes of these co-factors are much smaller in Agency states than in the CBRTW states, even though the signs are the same. In CBRTW states but not Agency states, black teachers and teachers with doctorate degrees are more likely to join a union. Even when teachers are covered by a CB agreement there is a downward time trend in union membership in CBRTW states. In Agency states, but not in CBRTW states, teachers working in larger schools or in areas with a higher cost of living are more likely to be union members. Union membership rates are stable across survey years.