Copper is an essential trade. In 2012, China accounted for 43.1% of all global copper demand, or more than five times the amount acquired by the US that same year. A modern economy can't grow without copper. One way to get that metal is to dig holes in the ground; the other is from scrap. Since the mid-1990s, China has taken both approaches, with scrap accounting for more than half of all Chinese copper production every year (peaking at 74% in 2000). Because China is still a developing economy, it doesn't throw away enough stuff to be self-sufficient. Thus, for the last decade it's imported more than 70% of the scrap copper it uses. Meanwhile, the US, which throws away far more scrap metal than it can ever use, has become the world's most attractive market for the savvy Chinese buyer.