Chinese have never had difficulty reproducing, as evidenced by their population which is offically reported at 1.3 billion but which outside observers think is 1.4 or 1.45 billion (what's 150 million extra people?).

However, it may be the case that half the Chinese male population over 40 THINK they are impotent. Which may be why the Chinese courts just overturned the Viagra patent so that cheap generic Viagras can now be made. Perhaps cheap generic viagra can kill the market for rhino nose.