Can there be some fixed cost in the long run? If not, why?
No, there cannot be any fixed cost in the long run. In the long run, all inputs are variable, which means there are no fixed inputs that the firm has to employ regardless of output level.
In the short run, at least one factor of production cannot be varied and therefore remains fixed. The cost that a firm incurs to employ these fixed inputs is called the total fixed cost (TFC). However, this concept does not apply to the long run.
Since there are no fixed costs in the long run, the total cost and the total variable cost coincide in the long run. The firm can adjust all its inputs according to production requirements.
Explanation
The textbook clearly states in section 3.7.2 that 'In the long run, all inputs are variable. There are no fixed costs.' This is the fundamental distinction between short run and long run. In the short run, at least one factor remains fixed, giving rise to fixed costs. But in the long run, the firm has the flexibility to vary all factors of production, eliminating the concept of fixed costs entirely.