The behavior of nuclear plant operators is consistent with a model of dynamic cost minimization. Utilities compare the cost the cost of generating power from their own nuclear plants with the cost of obtaining "replacement power" form other sources and then optimaze the respective shares over time.

Our results seem to provide substantial evidence that joint operating agreement's (JOA) act as constrained rather than unconstrained monopolists in setting ad rates and circulation levels. The constraint of having to produce two dailies binds tightly enough to yield JOA CPM's that are much...