Fig. 5: A causal loop diagram based on Sterman’s expanded feedback view of the world.

The illustrative framework presented here is not comprehensive but is intended to demonstrate the added value of adopting a feedback-oriented perspective aligned with Sterman’s (2002) ‘feedback view of the world.’ In different settings and at different times, the balance of power between these loops may vary, demonstrating that a variety of behaviours over time are possible. For example, the importance of the health and revenue goals may vary substantially across settings, both in practice and in framing to the public. Depending on which loops dominate, it is possible for the continuance of the tax policy itself to be maintained, strengthened, eroded or repealed over time. Tax repeal would be represented as a complete decrease in the ‘Introduction and continuance of the Tax’ variable. This reflects what we see in practice—SSB taxes have been introduced, increased^59,80, threatened⁸¹ and repealed⁸² in a variety of settings. Trends in SSB consumption may also vary depending on which loops prevail, with consumer and industry strategies highlighting potential policy resistance with respect to the health goal. This type of conceptual framework, underpinned by key systems thinking concepts, may enable identification upfront of areas of potential policy resistance. Link polarity is (+) unless otherwise shown.