This paper extends the Harris-Todaro model to include the possibility
of international labor movement and analyze the effectiveness of some
development policies, for example, wage subsidies and an import tariff
. This possibility will change the conventional results that these pol
icies raise the welfare from the laissez-faire level. We show that the
se policies lower the welfare in terms of internal (domestic) labor, b
ut they improve the welfare if foreign labor is discriminated by wage
tax, exploitation or other practices.