In this paper we investigate the economic effects of deregulation of s
hop opening hours legislation. The theoretical literature is rather mi
xed about the possible effects of such a policy. Using an empirical mo
del for optimal retail behavior, it is shown that the economic potenti
al can be high. It is demonstrated that employment goes up mainly beca
use of an increase in threshold labor. However, the magnitude of this
effect depends on the average number of additional hours as a conseque
nce of deregulation. Therefore, by using the model for optimal retail
behavior an optimal rule for extending opening hours is given. This ru
le implies that the potential for longer opening hours is high. It is,
however, shown that in the noncooperative equilibrium this potential
is higher than in the cooperative equilibrium, and that large-scale st
ores gain more from this deregulation.