Robinson, John P., and Geoffrey Godbey.  Time For Life: The Surprising Ways Americans Use Their Time
U.S.A: 1997
ISBN 0271016523,

Page 316

To be happier and wiser, it is easier to increase appreciation levels more than efficiency levels. Only by appreciating more can we hope to have a sustainable society. While efficiency, at least as envisioned in American society, always starts with wanting more, appreciating may start both with valuing more what is already here and with wanting less.