To develop the understanding of public sector growth, this paper addresses the determinants of one important component of public spending, public education. Disaggregation of school expenditure allows for an analysis of how different decisions at the national and the local government level contribute to increased spending. A bargaining model between the central government and a teacher union is combined with a demand model of educational services at the local government level. Political characteristics are assumed to influence the central government bargaining strength over teacher wages and working hours. The model is implemented using a database for economic, political and school factors in Norway during 1880-1990. Political strength, measured as stable government and low party fragmentation of parliament, is shown to be important to hold down teacher employment. Socialist orientation of the government tends to drive up both teacher wages and employment. The inelastic response of local governments to centrally determined cost factors imply that they are not able to hold back spending growth following higher costs.