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

\begin{array}{l} Δ {\bar{N}}_{t}^{B} = \sum_{i} \frac{(N_{i, t} + N_{i, t - 1})}{2} . Δ f_{i, t} & Δ {\bar{U}}_{t}^{B} = \sum_{i} \frac{(U_{i, t} + U_{i, t - 1})}{2} . Δ ν_{i, t} \\ Δ {\bar{N}}_{t}^{W} = \sum_{i} \frac{(f_{i, t} + f_{i, t - 1})}{2} . Δ N_{i, t} & Δ {\bar{U}}_{t}^{W} = \sum_{i} \frac{(ν_{i, t} + ν_{i, t - 1})}{2} . Δ U_{i, t} \\ f_{i, t} = \frac{F_{i, t}}{\sum_{j} F_{j, t}} & ν_{i, t} = \frac{V_{i, t}}{\sum_{j} V_{j, t}} . \end{array}