Minimum detectable effect size for main outcomes (accounting for sample
design and clustering)
With N=45/treatment we can detect a difference of at least d=0.3 in bids for a sigma = 0.7 and an Intra-class Correlation Coefficient across rounds of up to 0.3.
Values for sigma and differences in bids are based on: Čagalj, Marin & Morawetz, Ulrich & Haas, Rainer. (2013). Willingness to pay for conventional and organic food products in Croatia.