. Author manuscript; available in PMC: 2015 Aug 25.
Published in final edited form as: Soc Indic Res. 2014 Sep 13;123(3):625–660. doi: 10.1007/s11205-014-0753-0
Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
Fig. 1.
Time gap in responses between first and second wave