[D] Why are there not much labs that focus on reinforcement learning?

Even in MIT, UCB, Stanford, and CMU, only a handful of labs focus on RL. For example, in Berkeley it seems Abbeel and Levine's labs are the only labs that focus on RL. Outside of these schools and UMass, Brown, Harvard, and UT Austin, there are not many labs that focus on RL. Are there professors focusing on RL in schools like Cornell, Columbia, Georgia tech, UMD, UMich, etc? Also, why do you think there are not many people working …

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