We present a novel mechanism to elicit the willingness to pay (WTP) for multiple rather than for single units of a good. At each price of the canonical multiple price list (MPL) approach, we elicit varying multi-unit demand instead of the options whether to buy one unit or not. The multi-unit MPL (muMPL) retains the simplicity of the MPL without adding much complexity, is field-ready, and generates rich, truthful, and reasonably precise WTP data to estimate a demand curve. Finally, we showcase our mechanism in a challenging field environment.
