the fixed fees such that all the constraints (10) will be binding, we have Vr = 1,.., R
∑ [(ps - ws - c,)s,(p) - Fs]= ∑ [(pf - ws - cs)ss(pfr) - Fs]
s∈Sr s∈Sr ∖Gfr
In general, if constraints (10) are satisfied, the constraints (9) will be satisfied. The binding
constraints (10) imply that the sum of fixed fees paid for the products of f sold through r is
V Fs = V [(Ps - ws - cs')Ss(p) - (pfsr - Ws - cs)Ss(pfr )]
s∈Gfr s∈Sr
because ss(pfr ) = 0 when s ∈ Gfr.
Using this expression, one can rewrite the profit of the manufacturer f as
∏f = Σ2 [(ws - Ms)ss(p)+ Fs] = (W - G)ss (P)F Er = 1 ∑ Fs
s∈Gf s∈Gf s∈Gfr
= Σ (ws - Ms)ss(p) + Σr=1 Σ [(ps - ws - cs')Ss(p) - (pfsr - ws - cs)ss(Pf )]
s∈Gf s∈Sr
because ^r=∖Gfl- = Gf (and Gfr ∩ Gfrf = 0). The manufacturer’s profit is then
J
∏f = ^ (Ws - Ms)ss(p) + ^ (pPs - Ws - cs')Ss(p) - (p{ri'sf - Ws - c.. ) Ss ( pfrs ) (11)
s∈Gf s = 1
where r(s) denotes the retailer of product s (∈ {1,.., J}).
We will also consider a simpler case where constraints (10) do not exist because it is assumed
that if one offer is rejected then all offers must be rejected as in Bonnet and Dubois (2010). Then,
the outside opportunities depend on a fixed exogenous reservation utility and we will say that the
buyer power of retailer is exogenous.
3.2.1 With Resale Price Maintenance
Let’s consider the case where manufacturers use resale price maintenance (RPM) in their
contracts with retailers. Then, manufacturers can choose retail prices while the wholesale prices
have no direct effect on profit. In this case, the vectors of prices p>fr are such that pfr = p⅛ if
i ∈ Gfr and the profit (11) of manufacturer f can then be written as5
∏f = ∑s∈g (ws - Vs)ss(p) + ^s=1 (ps - ws - cs] [ss(p) - ss(pfr(s))]
5Because also ss(pfr^s^) = 0, pfr = ÷∞ for s ∈ Gfr and by convention ss(pfr(s))pfr = 0.
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