Personal
In my spare time I try to stay active (physically and mentally). With two young kids, we are always just trying to keep up.
This includes lots of hiking and skiing. I have completed the 48 4,000 ft. peaks in New Hampshire and am now working through the 14,000 ft. peaks in Colorado.

Skiing (all over the Northeast, Tahoe, and of course Colorado). The best is hiking to ski!

I also like to play soccer and volleyball.
And when I have/had more free time I play fantasy sports and moonlight doing football sports analytics. My colleagues Aaron Johnson, Alex Stimpson, and I have written two papers (here and here) for the MIT Sloan Sports Analytics Conference.