For an example of the latter, observe this HN thread: https://news.ycombinator.com/item?id=7042469
https://news.ycombinator.com/item?id=6725096
http://www2.econ.iastate.edu/tesfatsi/WhyEconomistsShunSimul...
For an example of the latter, observe this HN thread: https://news.ycombinator.com/item?id=7042469