Well-endowed rating systems: How modified defaults can lead to more sustainable performance

Rating systems are often used as design/decision tools to evaluate, grade, and reward infrastructure projects that meet sustainability criteria such as reductions in greenhouse gas emissions, preservation of wildlife habitat, and accessibility to community cultural resources. Embedded within any such rating system is choice architecture, which refers to the way information is presented to a decision maker. This research examines the impact on design choices of changes to defaults in the choice architecture of the Envision rating system for sustainable infrastructure. Currently, the default score in each category of Envision is zero points. Points are earned by improving upon industry norms. To test the impact of changing these defaults, participants (senior-level and graduate students) randomly received either the current Envision version or a modified version with a higher default score, endowing participants with points in sustainability. All participants used their randomly assigned rating system to design an outdoor community center and stream restoration brownfield site. Simply modifying the default, by endowing points, led to setting significantly higher design goals. There were no significant differences in other variables measured, including student motivation or perceptions about Envision or sustainability. These findings suggest that how choices are presented to engineers influences their decision-making process and can lead to higher sustainability goals. The construction engineering and management community can use this understanding to encourage more desired infrastructure outcomes.