A strike by miners in Peru coupled with higher-than-expected demand from the United States has made copper markets jittery, sending prices up to $8,600 per metric ton the week of July 6. The strike, the fourth one in 2008, comes on the heels of a violent strike that shut down roads in Moquegua state and involved laborers taking law enforcement officials hostage. The laborers have been demanding a greater share of profits and better working conditions from the mine operators and the government. The Peruvian government has stepped into the dispute, negotiating with laborers and passing legislation to guarantee more rights and benefits to subcontracted mining employees. The bill did not have the intended effect of putting off the week's strikes, but it did show that the government is willing to take a hand in stabilizing the unrest. Indeed, the government's interest in ensuring stability in the mining industry is substantial. Mining comprises nearly 7 percent of gross domestic product and around 60 percent of government tax revenue. Peru is the second-largest copper producer in the world, and all the big players are involved there, including mining giants such as Southern Copper, BHP Billiton, Xstrata, Barrick Gold, Shougang Hierro, Volcan and many others. The copper market has been on the rise during the past several years due to a variety of factors, including increased demand from China. With Peru's important role in the copper market, it is no wonder that the recent strikes in Peru have made investors nervous. Although the strikes may continue despite government efforts to appease the miners, the potential long-term impact of this series of strikes appears to be relatively minimal. So far, mine operators have reported that, by using temporary workers, they have been able to offset the disruptions of the strike and that output has not suffered.