Apple and its key manufacturing partner, Foxconn, have been justifiably criticized for their labor practices in China, which include excessive, oppressive and illegal overtime hours, hazardous conditions, inappropriate and sometimes forced labor of 16-18 year-old student “interns” on night shifts, and wages so low that 64 percent of workers claim they don’t cover basic needs.

Many observers have remarked that with Apple’s gigantic profits, it can afford to ensure better treatment of its production workforce. A close examination of the iPhone’s cost structure leaves no doubt.

Various market researchers, including iSuppli and Horace Dediu of Asymco, have broken down the costs of the iPhone, which Apple sold to wireless carriers for an average price of $630 in the fourth quarter of 2011. All agree that Foxconn’s assembly cost— approximately $15, or 2% of the total—is a miniscule part of the iPhone’s cost. Apple’s estimated $319 profit per phone is at least 20 times the cost of producing the iPhone. In fact, because the labor cost is only part of Foxconn’s costs, which include energy, property, and its own profit, Apple’s profit per phone is more than 20 times the labor cost.