3.2 Spatio-temporal concentration of firm entries
Due to the current scarcity of geo-referenced information about contextual spatial and temporal
heterogeneity, the temporal intensity
t
of the firm entries is estimated using a standard kernel
density estimator applied to the distribution of the years of firm entries. For the same reason, the
spatial intensity
i
sm
, for any ith firm entry location, is estimated using the following spatial
kernel estimator (Baddeley et al., 2000):