https://www.washingtonpost.com/opinions/why-is-the-number-of-us-start-ups-falling/2016/05/19/53fe8e04-1ded-11e6-9c81-4be1c14fb8c8_story.html
The piece has some very interesting observations, including that the decline in start-ups may be generational. Baby boomers were great entrepreneurs, the article observes, but succeeding generations have been less likely to start their own companies.
I think it's an interesting piece and worth a read.