… is from page 15 of David Rose’s excellent 2011 book, The Moral Foundation of Economic Behavior (links added):
Yuriy Gorodnichenko and Gerard Roland (2010) …. presented a model showing that while an ethic of individualism produces dynamic effects on growth, an ethic of collectivism produces only static gains. They also found evidence that individualism significantly contributes to long-run growth. In a subsequent paper (Gorodnichenko and Roland, 2011) they explored the effect that other factors might have on long-run growth and found that individualism was the most important and robustly significant factor of all.