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create the dyadic population measure. The annual percentage change was then calculated
from total dyadic population. Any increase in population within the dyad should increase
the burden placed on the water supply of the state. When jointly considered, population
change and precipitation should capture the water stress experienced by the dyad.
Although there are clearly other variables that could be used to measure the demand
placed on water resources, there is a problem of obtaining consistent measures over the
entire series for such things as agricultural development and industrialization.
Party Similarity. In the second model a measure of party similarity of the governors of
each dyad is used. This is used as a control variable. State leaders that share a common
political ideology may attempt to resolve their differences outside of the court system.
This could bias the results downward if omitted from the model, so it was included. The
variable was coded as a one when both governors belonged to the same party and as a
zero when the governors belonged to different parties. In the sample, there were only
Democrats and Republicans; there were no independent or third party governors in any of
these states during this period of study.
Analysis
The most fundamental question of this project is when do agreements fail?
Although we only have completed data for the Colorado River we do have preliminary
data for the entire United States. By looking at some simple descriptive statistics a few
patterns become clear. The first pattern is that with the exception of one case involving
the Potomac River all of the legal challenges were confined to agreements regulating the
Convention