US Imports by Country and Goods

\[ \begin{aligned} t_{F,c} &= \text{reciprocal rate} \times t_{US,c} \\ \text{size share}_c &= \frac{\text{expenditure}_c}{\text{total expenditure}} \\ \text{size-adjusted foreign tariff} &= \text{size share}_c \times t_{F,c} \\ \ln(P_{world,c}) &= -0.5\,(t_{US,c} + \text{size-adjusted } t_{F,c}) + 0.5\,\min(t_{US,c}, \text{size-adjusted } t_{F,c}) \\ \text{Imports}_{c,h} &= \text{baseline imports}_c \times P_{world,c} \times (1+t_{US,c})^{\varepsilon_h} \times (1+t_{F,c})^{\varepsilon_h} \\ \varepsilon(y) &= \varepsilon_{SR} + (\varepsilon_{LR} - \varepsilon_{SR})\left[1 - e^{-\ln(2)\,y/\text{half-life}}\right] \end{aligned} \]