Géraldine Bocquého, Florence Jacquet, and Arnaud Reynaud, “Reversal and magnitude effects in long-term timepreferences: Results from a field experiment”, Economic Letters, vol. 120, n. 1, July 2013, pp. 108–111.
We use a multiple price list approach with real payments to elicit long-term time preferences on a sample of French farmers. Elicited individual discount rates vary with the time delay, which supports the existence of a reversal effect in long-term time preferences, and increase with rewards, which contradicts the usual magnitude effect finding.