  There is an increasing need to hold players responsible for negative or
positive impact that take place elsewhere in a value chain or a network. For
example, countries or companies are held more and more responsible for their
indirect carbon emissions. We introduce a responsibility value that allocates
the total impact of the value chain among the players, taking into account
their direct impact and their indirect impact through the underlying graph.
Moreover, we show that the responsibility value satisfies a set of natural yet
important properties.
