(1995) that increased import competition may reduce firm size and scale efficiency.
Consider n domestic firms and nh foreign firms competing a la Cournot in an industry producing
a homogeneous good. Domestic and foreign firms employ the same production technology, featuring
a fixed cost f and a constant marginal cost 1∕φ. Markets are segmented, as in Brander (1981). Let
τ h and τ f denote the ad valorem tariffs charged by the domestic and foreign country, respectively.
The profits of domestic and foreign firms (π and πh, respectively) are given by:
π =(ph - 1∕φ)qh + (pf ∕(1 +τf) - 1∕φ)qf - f (13)
π* = (ph∕(1 + τh) - 1∕φ)qh + (pf - 1∕φ)qf - f
Here, qh and q*h denote, respectively, domestic and foreign firms’ sales to the domestic market,
whereas qf and qf are domestic and foreign firms’ sales to the foreign market, respectively. ph and
pf are the final consumer prices in the domestic and foreign market, respectively.
Since the two markets are segmented (and marginal costs are constant), a firm’s choice of
output in one market is independent of its choice of output in the other market. Hence we can
concentrate on the domestic market to study the impact of τh on qh and qhh , noting that the impact
of τf on qf is analogous to that of τh on qhh . The first order conditions for profit maximization in
the domestic market are given by:
∂π
∂qh
∂πh
p0hqh + ph - 1∕φ = 0
p0hqhh + ph - (1 + τh)∕φ =0
(14)
Totally differentiating equations (14) with respect to qh, qhh and τh, using Cramer’s rule and
assuming that firms’ outputs are strategic substitutes, it is possible to show that:
∂q
∂τ h
> 0,
∂qh
∂τ h
<0
(15)
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