M D r , s = M B A S E r , s ∗ ( 1 + ( P R I r , s , t − 1 ∗ E X R A T E r − M P R I C r , s M P R I C r , s ∗ e l a s t r p r s ) ) e l m p r 1 ∗ ( 1 + ( P R I r , s , t − 1 ∗ E X R A T E r − M P R I C r , s M P R I C r , s − P R I r , s , t − 2 ∗ E X R A T E r , t − 1 − M P R I C r , s , t − 1 M P R I C r , s , t − 1 ∗ e l a s t r p r s ) ) e l m p r 2 {\displaystyle MD_{r,s}=MBASE_{r,s}*(1+({\frac {PRI_{r,s,t-1}*EXRATE_{r}-MPRIC_{r,s}}{MPRIC_{r,s}}}*\mathbf {elastrpr} _{s}))^{elmpr1}*(1+({\frac {PRI_{r,s,t-1}*EXRATE_{r}-MPRIC_{r,s}}{MPRIC_{r,s}}}-{\frac {PRI_{r,s,t-2}*EXRATE_{r,t-1}-MPRIC_{r,s,t-1}}{MPRIC_{r,s,t-1}}}*\mathbf {elastrpr} _{s}))^{elmpr2}}
