“…Given that the optimal output, 𝑄𝑇 𝑌 𝑖 , of banks 𝑖, 𝑖 = 1,• • • , 𝑁 at time 𝑡, is at the point where marginal cost, 𝑀𝐶 𝑖 , equals its marginal revenue, 𝑀𝑅 𝑖 , the ratio of the difference between the price, 𝑃 𝑖 , and the marginal cost, 𝑀𝐶 𝑖 , on price is the Lerner index denoted as 𝐿𝐼 𝑖 and expressed algebraically as shown in equation ( 1) (Flamini, Schumacher & McDonald, 2009).…”