I've also listed how many employees (and volunteers, if any) each think tanks has, based on the most recently available public records.
- Rand Corp.: Revenue = $261.9 million ($250.1 million = prior year revenue); $179.4 million net assets; 2051 employees; 11 volunteers
- Heritage: Revenue= $78.2 million ($69.2 million); $164.8 million net assets; 530 employees; 231 volunteers
- Aspen Institute: Revenue = $69 million ($66.5 million); 160.2 million net assets; 285 employees; 40 volunteers
- Brookings: Revenue = $67 million ($75.2 million); $299.3 million net assets; 545 employees
- Urban Institute: Revenue = $64.3 million ($62.7 million); $105 million net assets; 404 employees
- CFR: Revenue = $42.7 million ($28.7 million); $317.8 net assets; 317 employees
- Cato: Revenue = $40.4 million ($31.5 million); $51.9 million net assets; 200 employees
- CSIS: Revenue = $39.1 million ($29.3 million); $55.3 million net assets; 259 employees
- CAP: Revenue = $36.7 million ($38.6 million); $36.6 million net assets; 325 employees
- NBER: Revenue = $32.3 million ($25.7 million); $79.7 million net assets; 679 employees
- GMF: Revenue = $23.5 million ($12.9 million); $185.8 million net assets; 84 employees
- BPC: Revenue = $21.7 million ($24 million); $21.2 million net assets; 64 employees
- CEIP: Revenue = $20.9 million ($16.5 million); $252.6 million net assets; 124 employees
- Wilson Center: Revenue = $16.4 million ($9.5 million); $103.8 million net assets; 152 employees
- NAF: Revenue = $15.8 million ($15.6 million); $15.8 million net assets; 144 employees; 44 volunteers
- AEI: Revenue = $13.1 million ($52.5 million); $135.5 million net assets; 111 volunteers (I assume that that this means 111 employees, not volunteers)
- Hudson: Revenue = $9.8 million ($12.4 million); $14.6 million net assets; 79 employees; 200 volunteers (Interesting how there were so many volunteers listed...)
- PIIE: Revenue = $9.6 million ($13.8 million); $68.7 million net assets; 62 employees
- ACUS: Revenue = $7.9 million ($6.5 million); $5.3 million net assets; 46 employees; 25 volunteers
- Third Way: Revenue = $7.7 million ($8.3 million); $13.9 million net assets; 60 employees; 2 volunteers
- EPI: Revenue = $6.5 million ($7.8 million); $5.8 million net assets; 59 employees
- Stimson: Revenue = $6.1 million ($6.6 million); $1.9 million net assets; 56 employees; 58 volunteers
- CNAS: Revenue = $4.3 million ($6.1 million); $1.4 million net assets; 63 employees; 15 volunteers
- IPS: Revenue = $2.9 million ($3.6 million); $987,720 net assets; 46 employees; 56 volunteers
- Lexington Institute: Revenue = $2.1 million ($2.4 million); $3.3 million net assets; 7 employees
- CNP: Revenue = $2 million ($1.2 million); $1.5 million net assets; 11 employees