Threshold 21 (T21) is a System Dynamics based model designed to support national development planning. T21 is structured to analyze medium-to-long term development issues at the national level. The model integrates economic, social, and environmental aspects of development into a single framework. It covers a broad range of issues that countries around the world face on the path to sustainable development, including poverty, environmental degradation, food security, education, healthcare, economic growth, and demographic shifts. The model’s comprehensiveness, level of aggregation, and detailed adaptation to individual country characteristics make it ideally suited to support broad analysis of different governmental strategies and to complement existing budgetary models and other short-medium term planning tools.
T21 is useful at four levels of the policy development process:
(i) The participatory process of the model’s development provides insights on the coherence and consistency of objectives, hypotheses, and data used for policymaking across sectors specific to the country or area under analysis. This process provides valuable information to better understand the critical causal relations that determine how different policies and assumptions will affect future scenarios.
(ii) The base run simulation of the model provides insight into the key development issues a country might face in the future if no policy changes are made. This helps identify areas where action is needed.
(iii) The alternative scenarios that can be conducted based on policy propositions provide an understanding of how different strategic choices or external conditions can impact future development, and how sectoral policies synergistically interact.
(iv) The resulting strategic plan provides a clear basis for improved decision-making and action in the various sectors, as well as for monitoring and evaluation of performance and results over time. The transparency of the model’s scenario results and the involvement of relevant ministries and stakeholders in the development of the model create a broader basis of support for reaching consensus on the sustainable policies the model helps to identify.