Explaining the Solar Installation Cost Difference Between the U.S. and Germany

From MIT Technology Review:

In 2011, residential solar system installers paid a little over $1.80 per watt for solar panels in both Germany and the United States. In Germany, installers added $1.20 to the cost of the solar panel to complete an installation. But in the U.S., they tacked on $4.36 per watt, more than three times as much.