Comparison of a nearest neighbor and other approaches to the detection of space-time clustering

A new method based on nearest neighbor (NN) distances is proposed for testing whether space-time clustering exists in a series of occurrences of an event. Unlike the methods of Knox and Mantel, the NN procedure does not require specifying arbitrary constants for the calculations of the test statistic. Based on the results of a simulation experiment, the NN test procedure is recommended because of its control of the significance level and its power. If appropriate constants can be found for the other two methods, they would also do relatively well. The three methods are applied to a real data example from a public education program.