If you are interested in environmental economics, visit the web page of Professor Matthew Kahn
http://mek1966.googlepages.com/home

UCLA Department of Economics
http://www.econ.ucla.edu/

California Center for Population Research
http://www.ccpr.ucla.edu/

National Bureau of Economic Research
http://www.nber.org/

MIT Department of Economics
http://econ-www.mit.edu/