As an historian looking at the same great and prosperous cities of the past, I find three things in common: 1. Innovation enabled via diversity; ethnic /linguistic /religious/cultural enclaves encouraged and protected. (Eg. foreign contractors built King Solomon's temple complex). 2. Innovation via consistent economic drivers : Welcoming cultural forces consistently drove innovation via economic demand for intellectual product. Eg. the cultural need to move dirt drove adoption of the foreign (Chinese) wheelbarrow, thus revolutionising European economies that previously were limited to buckets. 3. Innovation via Intellectual hybridities (e.g.. Edmund Gunter's chain, by marrying decimals with the old measurements, enabled auditable surveys, revolutionising capitalism via new land exchange technology). Therefore I conclude that innovation has had these 3 necessary historical conditions, quite consistent with your thesis.