Estimating the effect of an external factor behind an input-output table

An input-output table represents a quantitative economic relation between different branches of industries and has been widely used. This paper proposes a new approach to analyze the input-output table. From the network derived from the table, we estimate the effect of an external factor which is behind the scene. By introducing imaginary node into the network so as not to change the current situation, we can obtain the hidden relation. The newly added links of the imaginary node represents the relation between the external factor and internal nodes. We demonstrate that the relation between industrial sectors and a government can be obtained from this method.