THE ELUSIVE QUEST FOR THE PERFECT INDEX OF CONCENTRATION - REPLY TO EGAN, ANDERTON, AND WEBER

In this response we correct an error in our earlier description of the RCO index We also confirm that the index is not bounded on the negati ve side as we had previously thought and we discuss the conditions und er which its value goes below-1. We consider defining concentration in terms of density rather than area and systematically compare area- an d density-based measures. We conclude that in spite of its methodologi cal imperfections RCO remains a useful and informative measure of spat ial concentration that can be safely used until a clearly superior alt ernative is identified.