ON THE INTERPRETATION OF FIXED INPUT COEFFICIENTS UNDER AGGREGATION*
研究了加总后固定投入系数是否仍为常数，推导了其变动范围的上下界，并给出了系数保持固定的充要条件，对投入产出模型的应用有重要参考。
ABSTRACT A fixed input coefficient is traditionally interpreted as the additional input from one sector that is required for an additional unit of output in another sector. It is shown that this ratio of increments is, in general, not fixed under aggregation. A tight upper and lower bound for its variation are derived. A necessary and sufficient condition for the ratio to be fixed is obtained. As a consequence, adopting the common assumption of fixed input coefficients implies that additional assumptions at any subaggregate level are required. Similar results are given for the Leontief inverse, whose typical element is usually interpreted as the additional output in one sector that is required for an additional unit of final demand in another sector.