L`effet-Wicksell prix

q=Q
L;k=K L
q=rk +w
w=w(r)
=wmax −f(r)
(f(0) = 0; f0(r)>0)

w(r)f(r)
w(r)f(r)
w(r)⇔f(r)⇒f(r) + f0(r)(0 −r)≤f(0)
⇔f0(r)≥f(r)
r
w(r)⇔f(r)⇒f(r) + f0(r)(0 −r)≥f(0)
⇔f0(r)≤f(r)
r
w(r)
A A wmax
w(r)
k r
k=q−w
r
=wmax −(wmax −f(r))
r
k=f(r)
r
r
dk
dr =1 r2(f0(r)r−f(r))
dk
dr
dk
dr (≥0⇔f0(r)≥f(r)
r
≤0⇔f0(r)≤f(r)
r
w(r)k
r w(r)
k r
f⇔ ∀x, y, f(x) + f0(x)(y−x)≤f(y)f⇔ ∀x, y, f(x) + f0(x)(y−x)≥f(y)