national multiple family submetering and allocation billing program ...

Table 5.30 Estimated water use before and after conversion, RUBS properties N=39
Std.
Mean Deviation
Estimated Annual Water Use per Unit Prior to Conversion 55.32 21.64
Estimated Annual Water Use per Unit After Conversion 52.85 21.37
Change in Estimated Annual Water Use Before and After Conversion -2.48 15.05
Percent of Properties That Decreased Annual Water Use per Unit 53.85%
Percent of Properties That Did Not Change Annual Water Use per Unit 7.69%
Percent of Properties That Increased Annual Water Use per Unit 38.46%
Estimated Annual Water Use per Unit Prior
to Conversion - Estimated Annual Water
Use per Unit After Conversion
Table 5.31 Paired samples test, RUBS properties
Paired Differences
Mean
Difference
Std.
Deviation
Std.
Error
Mean t df
P-
value
2.477 15.051 2.410 1.028 38 0.311
COMPARISON OF RESULTS WITH OTHER STUDIES
As described in Chapter 2 (Literature Review) there are a number of studies that have
examined water use in submetered and RUBS properties to explore the impacts of these billing
programs. One of the most striking differences between these previous studies and the National
Submetering and Allocation Billing Program Study is the sample size. Table 5.32 shows the
various sample sizes for the analyses from this study, as well as from other previous studies. It is
important to note that in this study, each analysis that is listed uses a subset of data from the
previous analysis, as each analysis becomes more and more refined. The large number of
properties in this study allowed for numerous statistical analyses with substantial statistical
power that were not possible with the small sample sizes of the previous studies.
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