Here, we develop a novel cognitive framework by organizing these interventions along six cognitive processes: attention, perception, memory, effort, intrinsic motivation and extrinsic motivation. In addition, we conduct a meta-analysis of field experiments (i.e. randomized controlled trials) that contained real behavioural measures (n = 184 papers, k = 184 observations, N = 2 245 373 participants) from 2008 to 2021 to examine the effect size of these interventions targeting each cognitive process. Our findings demonstrate that interventions changing effort are more effective than interventions changing intrinsic motivation, and nudge and sludge interventions had similar effect sizes.

Government policies and services can be hard to navigate for people who are already under pressure. By understanding the effects of scarcity, we can make these easier to access for the people who need them. https://bi.dpc.nsw.gov.au/blog/2018/12/13/a-guide-to-reducing-the-effects-of-scarcity/