The price of copper on international markets reached a six-year low recently, part of a bear market that is effecting all of the major industrial metals. At the same time, thefts of cooper and copper scrap in the U.S. has increased, testimony to the fact the news of tanking prices hasn’t yet reached the underworld. News stories on the theft of copper piping, wiring, and other materials have abounded in recent months.

The stolen copper makes its way onto a black market, much of it destined for export to China. At one time China, the world’s largest user of copper, accounting for 40 percent of global consumption, had a voracious appetite for copper scrap which it would then melt down and use in any number of manufactured products and components. But China’s demand for copper scrap has cratered in recent years.

Just two years ago demand for copper scrap as on the rise, as were prices, accounting, no doubt, too, for the increase in the number of thefts. In 2010 and 2011, refined copper from scrap grew faster than refined copper from mining.

The supply-and-demand picture for copper scrap has changed dramatically since. The International Copper Study Group (ICGS) characterizes the situation as a “permanent structural change” in China’s demand for copper scrap.

One factor that has influenced the picture was the development of a new generation of mills in China that don’t use scrap as an input. This has contributed to a 500,000-ton drop in global scrap use over the past seven years, according to the ICGS.

Another factor in the decline of scrap and the growth of copper refined from ore has been the oversupply in mining. The ICGS expects copper mine supply growth of 3.5 million tons in 2015 versus 2011.

As a result, world copper scrap exports were down 25 percent, or 1.45 million tons, between 2012 and 2014. Reported imports of copper scrap were down 15 percent in two years, according to the ICGS. U.S. copper scrap exports were down by nearly 10 percent in 2014. China is reporting lower levels of copper scrap imports and is paying less for copper scrap. At the same time, copper refined from ore was up between 2011 to 2014.

Peter Buxbaum is web editor of Global Trade.