Short-Run Industry equilibrium In a short-run, neither entry nor exit can occur Consequently, in a short-run equilibrium, some firms may earn positive economics profits, others may suffer economic losses, and still others may earn zero economic profit.Short-Run Industry Equilibrium In a short-run, neither entry nor exit can occur. Consequently, in a short-run equilibrium, some firms may earn positive economics profits, others may suffer economic losses, and still others may earn zero economic profit