* Published at ICLR 2018: https://openreview.net/forum?id=r1lUOzWCW .
v4: actually-final version: non-existence of unbiased estimators for IPMs and
FID; clarity edits to the main proof Access Model/Code and Paper
* Journal of Machine Learning Research, 17(152):1-40, 2016 * Final version appeared at JMLR, with supplement. Code:
https://bitbucket.org/szzoli/ite/. arXiv admin note: text overlap with
arXiv:1402.1754 Access Model/Code and Paper