function ans=RA(ret,parm1, parm2, lambda, n)

[jpdf1, pjpdf1]=poisson(ret, parm1, n);
[jpdf2, pjpdf2]=poisson(ret, parm2, n);

ans=(pjpdf2/jpdf2-pjpdf1/jpdf1)*lambda;


function [jpdf, pjpdf]=poisson(ret, parm, n)


jpdf=0;
pjpdf=0;

for i=0:n
    pdf=exp(-parm(5))*parm(5)^i/factorial(i)*(2*pi*(parm(2)^2+i*parm(4)^2))^(-0.5)*exp(-(ret-parm(1)-i*parm(3))^2/(2*(parm(2)^2+i*parm(4)^2)));
    jpdf=jpdf+pdf;
    pjpdf=pjpdf+pdf*(ret-parm(1)-i*parm(3))/(parm(2)^2+i*parm(4)^2);
end

n=15; % cut-off in the Poisson sum
lambda=4.3; % map from consumption to dividend
parm1 = [0.0832    0.1377   -0.0259    0.0407    1.5120]; %p:  mu, sigma, theta, delta, omega
parm2 = [0.0547    0.1377   -0.0482    0.0981    1.5120]; %p*

m=200; % number of returns
minret=-0.30; %smallest return
maxret=0.30; %highest return

ret=linspace(minret,maxret,m); %range of returns

RAV=zeros(1,m);  

for j=1:m
    RAV(j)=RA(ret(j),parm1, parm2, lambda, n);
end;

plot(ret, RAV)

return