A recent report from Salomon Smith Barney anticipated that there would be 17.9 million sq ft of data center rooms built or under construction in the U.S. by the end of 2001, an 80% increase over 2000. In her thesis (Energy Needs In An Internet Economy: A Closer Look At Data Centers, published May 2001), Jennifer Mitchell-Jackson of the Energy Resources Group at UC Berkeley uses the growth rates from the Salomon Smith Barney report to estimate total data center floor area in the United States at 25 million sq ft by 2003.