RDP 2014-07: International Trade Costs, Global Supply Chains and Value-added Trade in Australia Equation

\begin{array}{l} N_{i}^{D} = \frac{N_{i} \times \sum_{j \in D} a_{j i} N_{j}}{\sum_{j \in D} a_{j i} N_{j} + \sum_{j \in I} a_{j i} N_{j}} \\ N_{i}^{I} = \frac{N_{i} \times \sum_{j \in I} a_{j i} N_{j}}{\sum_{j \in D} a_{j i} N_{j} + \sum_{j \in I} a_{j i} N_{j}} . \end{array}