[ghaff]

Underpinning the book I referenced, the author Ian Morris put together a very detailed attempt to quantify the overall level of civilization [1].

Certainly after the Fall of Rome, the West declined precipitously. I've been reading a bit about that period in Europe recently and the extent of the decline is really quite staggering. It's uneven to be sure as areas of the Middle East, for example, didn't really fall as far.

In any case, China was arguably more advanced than Europe for a significant period and certainly didn't trail significantly until the industrial revolution in the West. (And the industrial revolution(s) pretty much swamped everything that came before.)

ADDED: The book is pretty light on the why behind the West's relative success but there's some speculation, as I recall, around centralized government and general conservatism caused China to miss out.

[1] http://pzacad.pitzer.edu/~lyamane/ianmorris.pdf