1if tract bounds river;
See Statlib and references there for details on the corrections. Converted to R format by Friedrich Leisch.
Gilley, O.W., and R. Kelley Pace (1996). On the Harrison and Rubinfeld Data. _Journal of Environmental Economics and Management_, *31*, 403-405. [Provided corrections and examined censoring.]
Newman, D.J. & Hettich, S. & Blake, C.L. & Merz, C.J. (1998). UCI Repository of machine learning databases [http://www.ics.uci.edu/~mlearn/MLRepository.html]. Irvine, CA: University of California, Department of Information and Computer Science.
Pace, R. Kelley, and O.W. Gilley (1997). Using the Spatial Configuration of the Data to Improve Estimation. _Journal of the Real Estate Finance and Economics_, *14*, 333-340. [Added georeferencing and spatial estimation.]