Changes

Recall that Reinganum (1979) has firms with marginal costs drawn from a distribution <math>G(m)\,</math>. Suppose that an individual firm's cost is <math>m_j\,</math>, and that a fraction <math>\lambda\,</math> (<math>\lambda \in \left [0,1 \right )\,</math>) of firms price above <math>r. </math>Then: <math> f(x) = \begin{cases} 1 & -1 \le x < 0 \\ \frac{1}{2} & x = 0 \\ 1 - x^2 & \mbox{otherwise} \end{cases} </math>