|
Center for American Progress (United States)
8
|
Brookings Institution (United States)
6
|
Carnegie Endowment for International Peace (United States)
4
|
|
International Institute for Strategic Studies (United Kingdom)
4
|
Centre for European Policy Studies (Belgium)
3
|
National Bureau of Economic Research (United States)
3
|
|
RAND Corporation (United States)
2
|
Science Policy Research Unit (United Kingdom)
2
|
Urban Institute (United States)
2
|
|
Institute for Ecological Economy Research (Germany)
1
|
