【摘要】This   paper generalizes Hwang and Mai's (Am Econ Rev 80:567-575; ) model to include   labor markets and shows that their results are still valid when the   difference of inverse demand slopes is large enough; while; when this   difference is small; a monopoly firm always chooses the same (boundary)   location under different pricing scenarios. In the latter situation; total   outputs are identical in different pricing scenarios; while the social   welfare under discriminatory pricing is definitely less than that of the mill   pricing. Our results are robust; no matter whether the commuting costs are   paid by the firm or workers; and no matter whether wages are discriminatory   or uniform.