Policy coherence to achieve the SDGs: using integrated simulation models to assess effective policies

Abstract

Coherently addressing the 17 Sustainable Development Goals requires planning tools that guide policy makers. Given the integrative nature of the SDGs, we believe that integrative modelling techniques are especially useful for this purpose. In this paper, we present and demonstrate the use of the new System Dynamics based iSDG family of models. We use a national model for Tanzania to analyse impacts of substantial investments in photovoltaic capacity. Our focus is on the impacts on three SDGs: SDG 3 on healthy lives and well-being, SDG 4 on education, and SDG 7 on energy. In our simulations, the investments in photovoltaics positively affect life expectancy, years of schooling and access to electricity. More importantly, the progress on these dimensions synergizes and leads to broader system-wide impacts. While this one national example illustrates the anticipated impact of an intervention in one specific area on several SDGs, the iSDG model can be used to support similar analyses for policies related to all the 17 SDGs, both individually and concurrently. We believe that integrated models such as the iSDG model can bring interlinks to the forefront and facilitate a shift to a discussion on development grounded in systems thinking.

Keywords: Agenda 2030; Integration; National development planning; SDGs; Sustainable development goals; Synergies; System dynamics; Trade-offs; policy coherence.

Fig. 1

Main sectors of the iSDG model. Based on Barney (2002)

Fig. 2

Overview of the iSDG subsectors. The outer green field includes the environment subsectors, the middle red field the society subsectors and the inner green field the economy and governance subsectors. Source: Millennium Institute (2016)

Fig. 3

A simplified system dynamics representation of the photovoltaic electricity capacity part of the model

Fig. 4

Potential causal chains between electricity access, life expectancy and years of schooling. Note that the many intermediates through which the effects are channelled are not included in the Figure

Fig. 5

A causal map displaying the relationships between electricity access and life expectancy (referred to as a ‘diamond diagram’). A ‘+’-sign represents a ceteris paribus positive causal relationships (an increase in A causes B to increase, all things equal) and a ‘-‘-sign represents a ceteris paribus negative causal relationship (an increase in A causes B to decrease, all things equal)

Fig. 6

A simplified causal loop diagram displaying the discussed relationships. Each arrow represents a positive causal relationship. The three bold arrows represent the links that were added to the model. R1, R2 and R3 represents reinforcing loops initiated by the added links

Fig. 7

Simulated behaviour of electricity access for the five policy options with the entire iSDG model simulated

Fig. 8

Simulated behaviour of average years of schooling for the five policy options with the entire iSDG model simulated

Fig. 9

Simulated behaviour of life expectancy for the five policy options with the entire iSDG model simulated