Who is the real maker of Apple iPod?

Who makes the Apple iPod? Here's a hint: It is not Apple. The company outsources the entire manufacture of the device to a number of Asian enterprises, among them Asustek, Inventec Appliances and Foxconn.

But this list of companies isn't a satisfactory answer either: They only do final assembly. What about the 451 parts that go into the iPod? Where are they made and by whom?

Three researchers at the University of California, Irvine - Greg Linden, Kenneth Kraemer and Jason Dedrick - applied some investigative cost accounting, using a report from Portelligent that examined all the parts that went into the iPod.

Their study, sponsored by the Sloan Foundation, offers a fascinating illustration of the complexity of the global economy, and how difficult it is to understand that complexity by using only conventional trade statistics.

The retail value of the 30-gigabyte video iPod that the authors examined was $299. The most expensive component in it was the hard drive, which was manufactured by Toshiba and costs about $73. The next most costly components were the display module (about $20), the video processor chip ($8) and the controller chip ($5). They estimated that the final assembly, done in China, costs only about $4 a unit.

One approach to tracing supply chain geography might be to attribute the cost of each component to the country of origin of its maker. So $73 of the cost of the iPod would be attributed to Japan, since Toshiba is a Japanese company, and the $13 cost of the two chips would be attributed to the United States, since the suppliers, Broadcom and PortalPlayer, are American companies, and so on.

But this method hides some important details. Toshiba may be a Japanese company, but it makes most of its hard drives in the Philippines and China. So how can one distribute the costs of the iPod components across the countries where they are manufactured in a meaningful way?

At each step of the production process, inputs like computer chips and a bare circuit board are converted into outputs like an assembled circuit board.

According to the authors' estimates, the $73 Toshiba hard drive in the iPod contains about $54 in parts and labor. So the value that Toshiba added to the hard drive was $19 plus its own direct labor costs.

Those clever folks at Apple figured out how to combine 451 mostly generic parts into a valuable product. They may not make the iPod, but they created it. In the end, that's what really matters.