It's important to try to better understand the effect of various measures on R. In the present situation in the US and Europe, though, what matters most is quic

It's important to try to better understand the effect of various measures on R. In the present situation in the US and Europe, though, what matters most is quickly reducing R. There will be time for more experimentation with different measures (e.g., different regions trying slightly different interventions) later, but right now, plausibility is the best guide.