"A number of reasons: 1. Google had 600 employees and no revenue at the time (this was January 2002, before ads, gmail, etc). You can't really do real research

"A number of reasons: 1. Google had 600 employees and no revenue at the time (this was January 2002, before ads, gmail, etc). You can't really do real research at that stage. My job would have involved a lot of corporate strategy, technology development for products, management, etc. I wanted to refocus on basic research in ML, vision, robotics, and computational neuroscience. 2. The salary was low. Obviously, the stock option package would have ended up stratospheric. But we had teenage sons getting close to college and needed cash. Housing is more expensive in Silicon Valley than in New Jersey. 3. My family didn't want to move to California. You can't uproot teenagers without them hating you for it. 4. I had just left AT&T and joined the NEC Research Institute in Princeton. I thought I could work on ML/vision/robotics/neuroscience there. It turns out the place was quickly disintegrating into an applied research lab and I left for NYU after 18 months. Had I joined, I think the research culture at Google would have been different. I might have made it a bit more open and a bit more ambitious a bit earlier. "