1.13 In long-run competitive equilibrium, P  MC 

SRATC  LRATC. Because P  MR, we can write the condition as P  MR  MC  SRATC 

LRATC. Now let’s look at the condition as consisting of four parts:

(a) P  MR,

(b) MR  MC,

(c) P 

SRATC, and

(d) SRATC  LRATC. To explain (b), why MR  MC, we say that this condition exists because the perfectly competitive firm attempts to maximize profits and this is how it does it. What are the explanations for (a), (c), and (d)?