Model concept, solver and details - IFs
Note: The documentation of IFs is 'under review' and is not yet 'published'!| Corresponding documentation | |
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| Previous versions | |
| Model information | |
| Model link | |
| Institution | Frederick S. Pardee Center for International Futures, University of Denver (Pardee Center), Colorado, USA, https://pardee.du.edu/. |
| Solution concept | |
| Solution method | Dynamic recursive with annual time steps through 2100. |
| Anticipation | Myopic |
International Futures (IFs) is a large-scale, long-term, integrated global modeling system. The system is dynamic recursive with 1-year time steps through 2100.
IFs is a tool for thinking about long-term global trends and strategic planning for the future. Among the unique features of the system is the extensive integration of models across human capacity, social, and natural systems. IFs contains highly integrated (hard-linked) models across demographic, economic, education, health, governance, agriculture, energy, infrastructure, water, climate and other subsystems for 186 countries interacting in the global system. The central purpose of IFs is to facilitate exploration of global futures through alternative scenarios.
IFs can help a user
• Understand the state of major global systems
• Explore long-term trends and consider where they might take us
• Learn about the dynamic interactions across global subsystems
• Clarify long-term organizational goals/priorities
• Develop alternative scenarios (if-then statements) about the future
• Investigate how different agent categories (households, firms and governments) can shape the future
IFs is integrated with a large database (more than 4,000 series) for its countries, most of which include data since 1960. The system is fully imbedded in an interactive interface, and it is both open source and freely available to users both on-line (www.ifs.du.edu) and in downloadable form. The interface facilitates data analysis, projection exploration and comparison, and flexible scenario analysis. The models of IFs and their interactions. Figure 1 shows the major hard-linked models within the IFs system.
The multistate demographic model uses a standard cohort-component representation. Fertility and mortality are endogenous in response to other drivers, including adult educational attainment from a full education model and 15 categories of mortality and morbidity from a health model. In the education model students flow by grade through primary, lower secondary upper secondary, and tertiary levels. In the health model, mortality and morbidity are age and sex specific.
The multisector economic model is general equilibrium, although the model uses changes in inventory stocks and relative prices to drive changes in supply and demand, chasing equilibrium over time rather than solving for it or iterating to it in every time cycle. This is consistent with actual market behavior and facilitates computational efficiency. The partial equilibrium physical agriculture model differentiates crop, meat and fish and generates calorie and protein availability. The partial equilibrium energy model differentiates coal, oil, natural gas, hydroelectric power, nuclear power, and renewable energy, tracking resources bases and production. Key variables from the agriculture and energy models, converted to monetary terms, override those of the same sectors in the economic model, while the integration across sectors in the economic model of variables including household, government and firm demand and savings/investment availability provide information to and constraints upon the physical models.