Anyone used conjoint analysis for sustainable packaging decisions?

Conjoint is actually perfect for this exact problem — it forces trade-offs so you get revealed preferences instead of stated ones, which cuts through the social desirability bias you're worried about. We ran a choice-based conjoint for a CPG client last year with eco-packaging as one attribute alongside price and convenience, and the willingness-to-pay numbers were way lower than their focus groups suggested. Sawtooth Software is the go-to tool if you need robust analysis.