In early 90, that was thirty years ago, my aunt and my uncle of mother side came from Mainland to visit us.  As younger generation to them, my elder brother and I chipped in $4,000 as "greeting present" and gave each of them $2,000. (then less than a months salary of mine) I will never forget the complexion my aunt evinced on the spot: a mixture of surprise, appreciation, and a little embarrassment.  In those days, $2,000 approximately valued over RMB10,000, that was a big fortune for ordinary people or a family in China Mainland.

But when my aunt showed her ID card to us, suddenly I realized the gap of wealth between Taiwan and China Mainland would be erased soon or later.  That is a well laminated plastic card with perfect hue and shape, having some function of data processing.  Do you know what kind of ID card we were using then?  A paper one of handwritings and pasted photo. 

The following video may tell you why the "national" wealth of Taiwan dropped from 45% of the the GDP of China Mainland in early 90 to 1/22 by now.          

https://www.ixigua.com/7140509381111579167?logTag=a87dfd49efb5541e9b0b