You reminded me of hedonics. I was looking for an excuse. . .
Hedonics a way of assigning a monetary value to improvements and adding that dollar-value to the GDP instead of using the nominal dollar amount. This makes sense vis-a-vis technology because its value explodes while simultaneously its cost gets cheaper. So less is spent for lots more production.
"so China manufacturing really 50 times greater than U.S."
I am not sure that hedonics apply because where's the productivity improvements? We're just talking exchange rates here. Aren't we?
However in this pdf file is an explanation by someone who knows what I tried to described;
to wit, "the speed and capacity of computers increases very rapidly – currently, computer quality is increasing about 13 percent per year. Computer quality generates increases in real output. If a production system is computerized and computer quality is increasing, then each time a new computer is added, or replaces an obsolete one, the system can produce more. This is conceptually true for nearly any kind of production system – for instance, processing of retail transactions, airline reservations, electronic banking, or computer control of automated production lines in manufacturing.
"If these quality improvements are not measured as part of computer output, then real computer output will be understated. For instance, in 2000, nominal investments in computers rose by $19.8 billion dollars, an increase of 20.8 percent. However, the real value of computer investment rose by $86.4 billion. The real rate of change was 39.7 percent, nearly twice as large as the nominal rate of change of 20.8 percent."