Using the contributor-region shares from calc_trades_concentration:

\[a_{rod} = \left|\sum_{j\in r}c_{od,j}\right|, \qquad s_{rod} = \frac{a_{rod}}{\sum_q a_{qod}}, \qquad \mathrm{Exposure}_{od}(A) = \sum_{r\in A}s_{rod}.\]

exposed_to selects the set A of contributor Regions. Exposure is a fraction between zero and one. A zero denominator produces zero shares and zero exposure. Contributors are summed by Region before taking absolute values. Region clusters affect the trade axes; exposed_to still selects original contributor Regions.

All other selectors follow calc_trades_content. The result is a Region-by-Region DataFrame of exposure fractions, or a dictionary of DataFrames when multiple scenarios are requested.

Database.calc_trades_exposure(

indicator,

exposed_to,

item=None,

scenario='baseline',

method='total',

clusters=None,

clusters_direction='both',

intermediate=True,

final=True,

aggregate=True,

)

Calculate embodied trade-content exposure to one or more contributor Regions.

This method returns the share of absolute contributor-region content attributable to the selected Regions behind calc_trades_content(..., breakdown=True).