BE101 Nudge Challenge

The Trolley Nudge

Overview

• Located in large Western supermarkets• Objective is to reduce purchase of unhealthy food

(red) and increase purchase of healthy food (green)• Reliance of succession of visual cues

(red/amber/green) in floor colour of aisles, products on shelves and compartments of shopping trolley

• Measurement of choice at check-out (billed amounts of red/amber/green goods)

Experiment

• Monitor purchases ex-ante, after classifying goods as red, amber green

• Score purchase quality as %Green Spend + %Amber Spend * 0.5, permitting an index range 100% (healthy) to 0% (unhealthy)

• Plot distribution of score for a week’s shopping (possibly normal distribution)

• Repeat after red/amber/green nudge exercise• Compare ex-post distribution to ex-ante to measure

effectiveness of intervention

Further Analysis

Segment shoppers by ex-ante behaviour:• Size of basket• % unhealthy choicesAnalyze change in distribution after intervention

for each segment

Characterize group most and least resistance to change by contents of original shopping basket