W O R L D I M E M = S U M I M + S U M E X 2 {\displaystyle WORLDIMEM={\frac {SUMIM+SUMEX}{2}}}
if M I G R A T E r > 0 {\displaystyle MIGRATE_{r}>0} then M I G R A N T S r = M I G R A T E r ∗ P O P r ∗ W O R L D I M E M S U M I M {\displaystyle MIGRANTS_{r}={\frac {MIGRATE_{r}*POP_{r}*WORLDIMEM}{SUMIM}}}
if M I G R A T E r ≤ 0 {\displaystyle MIGRATE_{r}\leq {0}} then <math>MIGRANTS_{r}=\frac{MIGRATE_{r}*POP_{r}*WORLDIMEM}{SUMEM}
then 
then <math>MIGRANTS_{r}=\frac{MIGRATE_{r}*POP_{r}*WORLDIMEM}{SUMEM}