The authors acknowledge Cynthia Rowe, Arlene Frank, and Dana Mills for their comments on previous versions of this manuscript
We thank M. Shattuck for help with data compilation, H. Kaplan for providing access to additional data, R. Raaum for statistical advice, and R. Peterson and M. Petersdorf for encouragement and feedback on
previous versions of the manuscript.
Thanks to C. Bondavalli, C. Lortie, J.A. Evans, I.T. Foster, J. Parker, P. Reinhold, J. Ranganathan and F.G. Sperone for suggestions on
a previous version of the manuscript.
The author sends
me a previous version of the manuscript that contained errors instead of the final edited version.
We thank Dr. Graeme Fairchild for his comments on
a previous version of the manuscript.
The authors also wish to thank Kathy Georgiades for helpful comments on
a previous version of the manuscript and Vanya Aggarwal for help with Census data abstraction.