We propose a model for studying the dynamics of economic structures. The model is based on qualitative information regarding structural dynamics, in particular, (a) the information on the geometrical properties of trajectories (and their domains) which are studied in structural change theory and (b) the empirical information from stylized facts of structural change. We show that structural change is path-dependent in this model and use this fact to restrict the number of future structural change scenarios significantly. We focus on labour-allocation-dynamics in a tree-sector-economy. However, our approach can be applied to other types of structural change (e.g. incomedistribution-dynamics).