Measuring the impact of spatial perturbations on the relationship between data privacy and validity of descriptive statistics

Table 2 Global Moran’s I statistic for each of the perturbation methods

Perturbation method	Global Moran’s I	Proportion of unperturbed I	Variance in I
Original data	0.49	1	0.49302
Random perturbation 50 m	0.54	0.91	0.54023
Random perturbation 250 m	0.82	0.6	0.82067
Random perturbation 500 m	0.89	0.55	0.88739
Random weighted perturbation 5 NN	0.57	0.86	0.56697
Random weighted perturbation 50 NN	0.58	0.84	0.57983
Donut between 5 and 50 m	0.55	0.89	0.54593
Donut between 50 and 250 m	0.8	0.61	0.80124
Affine shear	0.54	0.91	0.53597
Voronoi masked	0.48	1.02	0.48222
Grid center w/100 m cells	0.36	1.36	0.35639
Grid center w/250 m cells	0.3	1.63	0.30335
Grid line w/100 m cells	0.47	1.04	0.47285
Grid line w/250 m cells	0.44	1.11	0.43534

ISSN: 1476-072X