Key points are not available for this paper at this time.
Krishna Srinivasan, and S. Sriramachandran for useful discussions. This paper draws upon work with my colleagues, Prachi Mishra and Petia Topalova. An anonymous referee and the editors provided helpful comments. Manzoor Gill and Thoihen Singh provided excellent assistance with data. 2 I.
Arvind Subramanian (Fri,) studied this question.