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. Author manuscript; available in PMC: 2017 Jun 15.
Published in final edited form as: Ann Am Assoc Geogr. 2016 Jun 17;106(5):1013–1029. doi: 10.1080/24694452.2016.1187060

Table 4.

Distribution of tracts by proportional error in estimate

Exact < 1% 1-2.99% 3-4.99% 5-10% > 10%

Tracts with no change (n=49,757)
    Areal interpolation (inc. water area) 0.140 0.680 0.111 0.024 0.018 0.025
    Areal interpolation (land only) 0.145 0.695 0.110 0.023 0.017 0.010
    NCDB 0.086 0.596 0.189 0.062 0.038 0.028
    LTDB 0.157 0.699 0.098 0.021 0.015 0.010
    NHGIS 0.160 0.700 0.095 0.020 0.015 0.010
Many to one tracts (n=981)
    Areal interpolation (inc. water area) 0.115 0.616 0.154 0.041 0.030 0.045
    Areal interpolation (land only) 0.120 0.640 0.148 0.038 0.023 0.031
    NCDB 0.037 0.412 0.301 0.119 0.080 0.052
    LTDB 0.138 0.648 0.127 0.034 0.024 0.029
    NHGIS 0.140 0.647 0.123 0.038 0.023 0.029
One to many tracts – no divided block (n=6,138)
    Areal interpolation (inc. water area) 0.000 0.022 0.045 0.047 0.115 0.770
    Areal interpolation (land only) 0.000 0.020 0.045 0.049 0.119 0.766
    NCDB 0.000 0.022 0.046 0.048 0.115 0.770
    LTDB 0.196 0.632 0.104 0.027 0.023 0.018
    NHGIS 0.196 0.632 0.104 0.027 0.023 0.018
Many to many tracts – no divided block (n=2,279)
    Areal interpolation (inc. water area) 0.004 0.129 0.171 0.095 0.130 0.472
    Areal interpolation (land only) 0.004 0.132 0.172 0.098 0.134 0.459
    NCDB 0.004 0.118 0.172 0.100 0.133 0.472
    LTDB 0.221 0.592 0.104 0.032 0.025 0.026
    NHGIS 0.221 0.592 0.104 0.032 0.025 0.026
One to many tracts – with divided block (n=6,307)
    Areal interpolation (inc. water area) 0.001 0.020 0.039 0.038 0.079 0.823
    Areal interpolation (land only) 0.001 0.020 0.040 0.039 0.084 0.816
    NCDB 0.001 0.021 0.039 0.037 0.081 0.822
    LTDB 0.055 0.563 0.183 0.060 0.062 0.076
    NHGIS 0.062 0.613 0.162 0.052 0.048 0.063
Many to many tracts – with divided block (n=6,743)
    Areal interpolation (inc. water area) 0.004 0.194 0.204 0.086 0.101 0.410
    Areal interpolation (land only) 0.004 0.193 0.213 0.088 0.104 0.398
    NCDB 0.005 0.183 0.198 0.092 0.108 0.415
    LTDB 0.057 0.530 0.205 0.064 0.053 0.090
    NHGIS 0.066 0.595 0.175 0.050 0.042 0.073