I thank Prof. Campbell (June 19) for answering my question.

As I understand it, his argument is that urbanization, as the second independent variable, was the driving force that led to the equilibrium one would predict for this [old] electoral system. Empirically, I agree with the explanation, but then, what would have happened if there were no urbanization? Would we have had the same proliferation of parties as we saw in the 1960, and as expected from the electoral system?

It seems to me if we need a second variable for electoral systems to fulfill its expected outcomes, it seems to diminish considerably the power of the theory (and thus we are left unsure of the results of the new electoral system).

Another question is; to what extend can the electoral system explain the decrease in the number of factions (especially within the LDP) which followed the stabilization of the number of (opposition) parties? Or is it totally unrelated?

If these questions have already been discussed by specialists, I would greatly appreciate it if someone could post references.

Thank you

Nobuhiro Hiwatari
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