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◗✉❛❧✐t② Pr♦✈✐s✐♦♥ ✐♥ ❛ ❙❡❛r❝❤ ❊♥❣✐♥❡ ❊♥✈✐r♦♥♠❡♥t

• ❡♦r❣✐♦s P❡tr♦♣♦✉❧♦s ✭❇r✉❡❣❡❧✮ ❛♥❞ ▼❛r✐❛ ❚❤❡❛♥♦

❚❛❣❛r❛❦✐ ✭❊q✉❛❧ ❙♦❝✐❡t②✮ ❈♦♥❢❡r❡♥❝❡ ♦♥ ❊✲❝♦♠♠❡r❝❡✱ ❉✐❣✐t❛❧ ❊❝♦♥♦♠② ❛♥❞ ❉❡❧✐✈❡r② ❙❡r✈✐❝❡s ❚♦✉❧♦✉s❡✱ ▼❛r❝❤ ✸✶✱ ✷✵✶✻

✶ ✴ ✶✹

■♥tr♦❞✉❝t✐♦♥

❙❡❛r❝❤ ❡♥❣✐♥❡ ♦r❣❛♥✐❝ r❡s✉❧ts ❛r❡ t❤❡ ♠❛✐♥ s♦✉r❝❡s ❢♦r tr❛✣❝ ✐♥ ✇❡❜s✐t❡s ✭❏❡r❛t❤✱ ▼❛ ❛♥❞ P❛r❦✱ ✷✵✶✸ ❛♥❞ ❇❛②❡✱ ❙❛♥t♦s ❛♥❞ ❲✐❧❞❡♥❜❡❡st✱ ✷✵✶✹✮ ❊✈❡r② ♣r♦♠✐♥❡♥t r❛♥❦ ♣♦s✐t✐♦♥ ✐♥ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡ r❡s✉❧ts ✐♥ ❛ ❤✐❣❤❡r ❝❧✐❝❦t❤r♦✉❣❤ r❛t❡ ✭●❧✐❝❦✱ ❘✐❝❤❛r❞s✱ ❙❛♣♦③❤♥✐❦♦✈ ❛♥❞ ❙❡❛❜r✐❣❤t✱ ✷✵✶✹✮ ❚❤❡ r❛♥❦✐♥❣ ♦❢ t❤❡ ✜r♠s ✐♥ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡ ✐s ❞❡t❡r♠✐♥❡❞ ❜② ❛♥ ❛❧❣♦r✐t❤♠ ✇❤✐❝❤ ✐s ♠✉❧t✐❞✐♠❡♥s✐♦♥❛❧✱ ✐♥❝❧✉❞✐♥❣ ❙❡❛r❝❤ ❊♥❣✐♥❡ ❖♣t✐♠✐③❛t✐♦♥ ✭❙❊❖✮ ❛♥❞ ♣r♦❞✉❝t q✉❛❧✐t②✮ ■♥ ❝♦♥tr❛st t♦ t❤❡ ❛✉❝t✐♦♥ ❛♣♣r♦❛❝❤ ♦❢ t❤❡ ♣❛✐❞ ♣❧❛❝❡♠❡♥t✱ ✜r♠s ✇❤✐❝❤ ✇✐s❤ t♦ ❣❛✐♥ ♣r♦♠✐♥❡♥❝❡ ✐♥ ♦r❣❛♥✐❝ r❡s✉❧ts s❤♦✉❧❞ ❝♦♠♣❧② ✇✐t❤ t❤❡ r❡q✉✐r❡♠❡♥ts ♦❢ t❤❡ ❛❧❣♦r✐t❤♠

✷ ✴ ✶✹

❖❜❥❡❝t✐✈❡s

❊✈❛❧✉❛t❡ t❤❡ ✐♠♣❛❝t ♦❢ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡ ❛❧❣♦r✐t❤♠ ❢♦r ♣r♦♠✐♥❡♥❝❡ ♦♥ ✜r♠s✬ ♦♣t✐♠❛❧ ❛❧❧♦❝❛t✐♦♥ ♦❢ ✐♥✈❡st♠❡♥ts ❜❡t✇❡❡♥ ❙❡❛r❝❤ ❊♥❣✐♥❡ ❖♣t✐♠✐③❛t✐♦♥ ✭❙❊❖✮ ❛♥❞ q✉❛❧✐t② ❙❊❖ ✭✇❤✐t❡✲❤❛t✮ ✈❛r✐❡s ❢r♦♠ ❞❡✈❡❧♦♣✐♥❣ s✐t❡ ❞❡s✐❣♥ ❛♥❞ ❝♦♥t❡♥t q✉❛❧✐t② ❛s ✇❡❧❧ ❛s ❜r❛♥❞ ❛✇❛r❡♥❡ss ❛♥❞ r❡♣r❡s❡♥t❛t✐♦♥ ❲❡ ✐♥✈❡st✐❣❛t❡ ✇❤❡t❤❡r ❛♥❞ ✉♥❞❡r ✇❤❛t ❝♦♥❞✐t✐♦♥s t❤❡ ❙❊❖ ✐♥✈❡st♠❡♥t ❧❡❛❞s t♦ ❛ ❞✐st♦rt✐♦♥ ✐♥ t❤❡ ❧❡✈❡❧ ♦❢ q✉❛❧✐t② ❛♥❞ ✐❢ ②❡st✱ ✐ts ✐♠♣❛❝t ♦♥ ❝♦♥s✉♠❡r s✉r♣❧✉s ❛♥❞ t♦t❛❧ ✇❡❧❢❛r❡

✸ ✴ ✶✹

▼♦❞❡❧✿ P❧❛②❡rs

❈♦♥s✉♠❡rs ♦❢ ♠❛ss ✶ t②♣❡ ❛ q✉❡r② ✐♥ ❛ s❡❛r❝❤ ❡♥❣✐♥❡✳ Pr❡❢❡r❡♥❝❡s✿ U =

• v − p

✐❢ ❝♦♥s✉♠❡r ♠❛t❝❤❡s ❛♥❞ ♣✉r❝❤❛s❡s ♦t❤❡r✇✐s❡ ✭✶✮ ❈♦♥s✉♠❡r ❧❡❛r♥s ❤✐s ✈❛❧✉❛t✐♦♥ ✇❤❡♥ ❤❡ ❛❝t✉❛❧❧② ❜✉②s t❤❡ ❣♦♦❞✿ v ∈ [v, v]✱ 0 ≤ v < v✱ G(v) ❛♥❞ g(v) > 0 ❚✇♦ ✜r♠s t❤❛t ❝♦♠♣❡t❡ ❢♦r ♣r♦♠✐♥❡♥❝❡ ✐♥ ❛ s❡❛r❝❤ ❡♥❣✐♥❡ ❜② ❝❤♦♦s✐♥❣ t❤❡✐r ❧❡✈❡❧ ♦❢ ❙❊❖ ❛♥❞ ♣r♦❞✉❝t q✉❛❧✐t② ❆ s❡❛r❝❤ ❡♥❣✐♥❡ r❛♥❦s t❤❡ t✇♦ ✜r♠s ❜❛s❡❞ ♦♥ ✐ts ❛❧❣♦r✐t❤♠ t❤❛t t❛❦❡s ✐♥t♦ ❛❝❝♦✉♥t ✜r♠s✬ ❝❤❛r❛❝t❡r✐st✐❝s s✉❝❤ ❛s t❤❡ ✐♥✈❡st♠❡♥ts ♦♥ q✉❛❧✐t② ❛♥❞ ❙❊❖

✹ ✴ ✶✹

❚✐♠✐♥❣

✶ ❋✐r♠s ❝♦♠♣❡t❡ ❛♥❞ ♠❛①✐♠✐③❡ t❤❡✐r ♣❛②♦✛ ❢✉♥❝t✐♦♥s ✇✐t❤

r❡s♣❡❝t t♦ q✉❛❧✐t② ❛♥❞ ✐♥✈❡st♠❡♥ts ♦♥ ❙❊❖

✷ ❋✐r♠s ❝❤♦♦s❡ t❤❡✐r ♣r✐❝✐♥❣ ❜❡❤❛✈✐♦r ✭♠♦♥♦♣♦❧✐st✐❝

❝♦♠♣❡t✐t✐♦♥✮

✸ ❚❤❡ s❡❛r❝❤ ❡♥❣✐♥❡ r❛♥❦s t❤❡ ✜r♠s ✹ ❈♦♥s✉♠❡rs ♦❜s❡r✈❡ t❤❡ r❛♥❦✐♥❣ ❛♥❞ t❤❡♥ t❤❡② ❞❡❝✐❞❡

✇❤✐❝❤ ✜r♠ t♦ ✈✐s✐t ❛♥❞ ✇❤❡t❤❡r t❤❡② ✇✐❧❧ ♣✉r❝❤❛s❡ ♦r ♥♦t

✺ ✴ ✶✹

❊q✉✐❧✐❜r✐✉♠ ❙tr❛t❡❣✐❡s

❈♦♥s✉♠❡rs ✇✐❧❧ ❝❤♦♦s❡ t♦ ❣♦ ✜rst❧② ♦♥ t❤❡ ✜r♠ t❤❛t ✐s r❛♥❦❡❞ ✜rst✳ ■❢ t❤❡② ♠❛t❝❤ t❤❡② ♣✉r❝❤❛s❡ ❛♥❞ t❤❡ ❣❛♠❡ st♦♣s✳ ❖t❤❡r✇✐s❡✱ t❤❡② ✈✐s✐t t❤❡ s❡❝♦♥❞ ✜r♠ ❜② ✐♥❝✉rr✐♥❣ ❛ r❡❧❛t✐✈❡❧② ❧♦✇ s❡❛r❝❤ ❝♦st µ✳ ■❢ t❤❡② ♠❛t❝❤ t❤❡② ♣✉r❝❤❛s❡✳ ❖t❤❡r✇✐s❡✱ t❤❡② ❡①✐t t❤❡ ♠❛r❦❡t✳ ❇❛s❡❞ ♦♥ t❤❡ ✐♠♣❧❡♠❡♥t❡❞ ❛❧❣♦r✐t❤♠✱ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡ r❛♥❦s t❤❡ ✜r♠s ❜❛s❡❞ ♦♥ ❜♦t❤ t❤❡ ❙❊❖ ❛♥❞ q✉❛❧✐t② ✐♥✈❡st♠❡♥t ♦✉t❝♦♠❡ ❋✐r♠s ✐♥ ❡q✉✐❧✐❜r✐✉♠ ❝❤❛r❣❡ t❤❡ ♠♦♥♦♣♦❧② ♣r✐❝❡ ❛♥❞ ❡❛r♥✿ p∗ = 1 − G(p) g(p) , Π∗ = [1 − G(p)]2 g(p) ✭✷✮

✻ ✴ ✶✹

P❛②♦✛ ❋✉♥❝t✐♦♥s

Πi = Π∗ (Φi(xi, x−i, Si, S−i)x−ixi + (1 − x−i)xi) − C(xi) − Ki(Si) ✭✸✮ ✇❤❡r❡ i = A, B ❛♥❞ Φi(xi, x−1, Si, S−i)✿ ✜r♠ ✐✬s ♣r♦❜❛❜✐❧✐t② ♦❢ ❜❡✐♥❣ r❛♥❦❡❞ ✜rst xi✿ ♠❛t❝❤✐♥❣ ♣r♦❜❛❜✐❧✐t② ♦❢ ✜r♠ ✐ ✇✐t❤ ❛ r❛♥❞♦♠❧② ❝❤♦s❡♥ ❝♦♥s✉♠❡r Si✿ ✜r♠ ✐✬s ✐♥✈❡st♠❡♥t ♦♥ ❙❊❖ C(·)✱ Ki(·)✿ ❆ss♦❝✐❛t❡❞ ❝♦sts

✼ ✴ ✶✹

❇❡♥❝❤♠❛r❦✿ ❙❡❛r❝❤ ❡♥❣✐♥❡ ❞♦❡s ♥♦t ❡①✐st

Pr♦♣♦s✐t✐♦♥ ❲❤❡♥ ❛ s❡❛r❝❤ ❡♥❣✐♥❡ ❛❞♠✐ts t❤❡ r❛♥❦✐♥❣ r❛♥❞♦♠❧② ❛♥❞ ✜r♠s ❛r❡ s②♠♠❡tr✐❝ ✭Φ = 1

2✮✱ t❤❡r❡ ❡①✐sts ❛ s②♠♠❡tr✐❝ ◆❛s❤

❡q✉✐❧✐❜r✐❛ ✐♥ ♣✉r❡ str❛t❡❣✐❡s ✇❤❡r❡ t❤❡ ✐♥✈❡st♠❡♥t ♦♥ ❙❊❖ ✐s ③❡r♦ ✇❤✐❧❡ t❤❡ q✉❛❧✐t② ✐s ❣✐✈❡♥ ❜②✿ xr =

• 2 Π∗−Cx

Π∗

✐❢ 0 < Π∗−Cx

Π∗

< 1

2

1 ♦t❤❡r✇✐s❡ ✭✹✮

✽ ✴ ✶✹

◗✉❛❧✐t② ❛♥❞ ❙❊❖ ✐♥ t❤❡ s❤♦rt✲r✉♥

◗✉❛❧✐t✐❡s ❛r❡ ✜①❡❞ ❋✐r♠s ♦♣t✐♠✐③❡ ✇✐t❤ r❡s♣❡❝t t♦ ❙❊❖✿ ❙②♠♠❡tr✐❝ ◆❛s❤ ❡q✉✐❧✐❜r✐✉♠ ❍♦✇ ❞♦❡s s❡❛r❝❤ ❡♥❣✐♥❡✬s ❛❧❣♦r✐t❤♠ ♣❡r❝❡✐✈❡s ❙❊❖ ❛♥❞ q✉❛❧✐t②❄

✶

■♥❞❡♣❡♥❞❡♥t✿

∂2Φi ∂Si∂xi = 0 ❛♥❞ ∂2Φi ∂Si∂x−i = 0

✷

❈♦♠♣❧❡♠❡♥ts✿

∂2Φi ∂Si∂xi > 0 ❛♥❞ ∂2Φi ∂Si∂x−i < 0

✸

❙✉❜st✐t✉t❡s✿

∂2Φi ∂Si∂xi < 0 ❛♥❞ ∂2Φi ∂Si∂x−i > 0

✾ ✴ ✶✹

◗✉❛❧✐t② ❛♥❞ ❙❊❖ ✐♥ t❤❡ s❤♦rt✲r✉♥ ✭✷✮

■♥❞❡♣❡♥❞❡♥t✿ ❡✈❡♥ ✐❢ t❤❡r❡ ✐s ❛s②♠♠❡tr② ✐♥ ♦✛❡r❡❞ q✉❛❧✐t✐❡s✱ ✜r♠s s❡❧❡❝t t❤❡ s❛♠❡ ❙❊❖ ✐♥ ❡q✉✐❧✐❜r✐✉♠ ❈♦♠♣❧❡♠❡♥ts✿ ❚❤❡ ✜r♠ t❤❛t ♦✛❡rs ❤✐❣❤❡r q✉❛❧✐t②✱ ❛❧s♦ s❡ts ❣r❡❛t❡r ❙❊❖ ❙✉❜st✐t✉t❡s✿ ❚❤❡ ✜r♠ t❤❛t ♦✛❡rs ❤✐❣❤❡r q✉❛❧✐t②✱ s❡ts ❧♦✇❡r ❙❊❖

✶✵ ✴ ✶✹

◗✉❛❧✐t② ❛♥❞ ❙❊❖ ✐♥ t❤❡ ❧♦♥❣✲r✉♥

Pr♦♣♦s✐t✐♦♥ ■❢ C(·) ✐s s✉✣❝✐❡♥t❧② ❝♦♥✈❡①✱ t❤❡r❡ ❡①✐sts ❛ s②♠♠❡tr✐❝ ♣✉r❡ ◆❛s❤ ❡q✉✐❧✐❜r✐✉♠ ✇❤✐❝❤ ✐s ❞❡✜♥❡❞ ❜②✿ Π∗ ∂Φ ∂x x2 + 1 − 1 2x

• = Cx,

Π∗∂Φ ∂S x2 = KS ✭✺✮ Pr♦♣♦s✐t✐♦♥ ❆t s✉❝❤ ◆❛s❤ ❡q✉✐❧✐❜r✐✉♠✱ ✐❢ q✉❛❧✐t② ❛♥❞ ❙❊❖ ❛r❡✿ ✐♥❞❡♣❡♥❞❡♥t✿ ◆♦ q✉❛❧✐t② ❞✐st♦rt✐♦♥ ❝♦♠♣❧❡♠❡♥ts✿ ✜r♠s ❛r❡ ♦✛❡r✐♥❣ ❤✐❣❤❡r q✉❛❧✐t② ✇❤❡♥ ❙❊❖ ✐s ❛❧❧♦✇❡❞ s✉❜st✐t✉t❡s✿ ✜r♠s ❛r❡ ♦✛❡r✐♥❣ ❧❡ss q✉❛❧✐t② ✇❤❡♥ ❙❊❖ ✐s ❛❧❧♦✇❡❞

✶✶ ✴ ✶✹

❙❤♦rt✲r✉♥ ✇❡❧❢❛r❡ ✐♠♣❧✐❝❛t✐♦♥s ❜② t❤❡ ♣r❡❝❡♥s❡ ♦❢ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡

Pr♦♣♦s✐t✐♦♥ ❚❤❡ ✐♠♣❛❝t ♦❢ t❤❡ ❡①✐st❡♥❝❡ ♦❢ s❡❛r❝❤ ❡♥❣✐♥❡ ♦♥ t❤❡ s❤♦rt✲r✉♥ ❝♦♥s✉♠❡r s✉r♣❧✉s ❛♥❞ t♦t❛❧ ✇❡❧❢❛r❡ ❞❡♣❡♥❞s ♦♥ ❝♦rr❡❧❛t✐♦♥ ❜❡t✇❡❡♥ q✉❛❧✐t② ❛♥❞ ❙❊❖✳ ❙♣❡❝✐✜❝❛❧❧②✱ ✐❢ t❤❡② ❛r❡ ✐♥❞❡♣❡♥❞❡♥t✿ ❈♦♥s✉♠❡r ❡①♣❡❝t❡❞ s✉r♣❧✉s ✐s ✇❡❛❦❧② ✐♥❝r❡❛s❡❞ ❜② t❤❡ ♣r❡s❡♥❝❡ ♦❢ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡✳ ❚♦t❛❧ ✇❡❧❢❛r❡ ✐s ❛❧s♦ ✐♥❝r❡❛s❡❞✱ ❜✉t✱ ♦♥❧② ✇❤❡♥ t❤❡ ♣r♦❜❛❜✐❧✐t② Φi ❢♦r t❤❡ ❤✐❣❤ q✉❛❧✐t② ✜r♠ ✐s s✉✣❝✐❡♥t❧② ❤✐❣❤ ❝♦♠♣❧❡♠❡♥ts✿ ❙❛♠❡ ✭q✉❛❧✐t❛t✐✈❡❧②✮ ❝♦♥❝❧✉s✐♦♥s ❛s ✐♥ t❤❡ ✐♥❞❡♣❡♥❞❡♥t ❝❛s❡ s✉❜st✐t✉t❡s✿ ❚❤❡ ✐♠♣❛❝t ♦♥ ❝♦♥s✉♠❡r s✉r♣❧✉s ❛♥❞ t♦t❛❧ ✇❡❧❢❛r❡ ✐s ❛♠❜✐❣✉♦✉s✳ P♦s✐t✐✈❡ ✐♠♣❛❝t r❡q✉✐r❡s ❢✉rt❤❡r r❡str✐❝t✐♦♥s ♦♥ Φi ♦❢ t❤❡ ❤✐❣❤ q✉❛❧✐t② ✜r♠✳

✶✷ ✴ ✶✹

▲♦♥❣✲r✉♥ ✇❡❧❢❛r❡ ✐♠♣❧✐❝❛t✐♦♥s ❜② t❤❡ ♣r❡❝❡♥s❡ ♦❢ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡

Pr♦♣♦s✐t✐♦♥ ❚❤❡ ✐♠♣❛❝t ♦❢ t❤❡ ❡①✐st❡♥❝❡ ♦❢ s❡❛r❝❤ ❡♥❣✐♥❡ ♦♥ t❤❡ s❤♦rt✲r✉♥ ❝♦♥s✉♠❡r s✉r♣❧✉s ❛♥❞ t♦t❛❧ ✇❡❧❢❛r❡ ❞❡♣❡♥❞s ♦♥ ❝♦rr❡❧❛t✐♦♥ ❜❡t✇❡❡♥ q✉❛❧✐t② ❛♥❞ ❙❊❖✳ ❙♣❡❝✐✜❝❛❧❧②✱ ✐❢ t❤❡② ❛r❡ ✐♥❞❡♣❡♥❞❡♥t✿ ❈♦♥s✉♠❡rs ❛r❡ ✐♥❞✐✛❡r❡♥t ✇❤✐❧❡ t♦t❛❧ ✇❡❧❢❛r❡ ❞❡❝r❡❛s❡s ❝♦♠♣❧❡♠❡♥ts✿ ❈♦♥s✉♠❡r s✉r♣❧✉s ✐♥❝r❡❛s❡s ✇❤✐❧❡ t❤❡ ✐♠♣❛❝t ♦♥ t♦t❛❧ ✇❡❧❢❛r❡ ✐s ❛♠❜✐❣✉♦✉s s✉❜st✐t✉t❡s✿ ❈♦♥s✉♠❡r s✉r♣❧✉s ❛♥❞ t♦t❛❧ ✇❡❧❢❛r❡ ❛r❡ r❡❞✉❝❡❞

✶✸ ✴ ✶✹

❉✐s❝✉ss✐♦♥

❈♦♠♣❧❡♠❡♥t❛r✐t② ❜❡t✇❡❡♥ q✉❛❧✐t② ❛♥❞ ❙❊❖ ❝❛♥ ❜❡ ✇❡❧❢❛r❡ ✐♠♣r♦✈✐♥❣ ❲❤❛t ❛r❡ t❤❡ ✐♥❝❡♥t✐✈❡s ♦❢ t❤❡ s❡❛r❝❤ ❡♥❣✐♥❡❄ ❈♦✉❧❞ ✇❡ ❞❡r✐✈❡ ❛♥② r❡❣✉❧❛t♦r② ✐♠♣❧✐❝❛t✐♦♥s ✭❢♦r ❡①❛♠♣❧❡✱ ❛❜♦✉t t❤❡ ❞✐s❝❧♦s✉r❡ ♦❢ t❤❡ ❛❧❣♦r✐t❤♠✮❄ ❈♦♠♣❡t✐t✐♦♥ ❛♠♦♥❣ s❡❛r❝❤ ❡♥❣✐♥❡s❄

✶✹ ✴ ✶✹