ndeed increase their happiness, and we hope we've done a bit of that here. References Ainslie. (L. & Haslam, N. (1992). Hyperbolic discounting. In G. Loewenstein. & J. Fitter (Eds.), Choice over time (pp. 57-92). New York: Russell Sage Foundation. Aknin. Barrington-Leigh, M., Dunn. E.W.. Helliwell, J.F.. B