Exogenous information and input-output updating: An evaluation

Input-output coefficients' intertemporal instability, costs, and time lags involved in the construction of survey-based tables necessitate employment of nonsurvey updating techniques. Analysts, however, may want to include exogenous information in the updating process. The issue, then, is whether this inclusion ameliorates or aggravates the results. This paper attempts to assess the wisdom of incorporating exogenous information into the updating procedure. First, using the naive, RAS, and LaGrangian techniques, the 1966 table of the former Soviet Union was updated to 1972. Next, treating the top 10 percent largest 1972 coefficients as exogenous estimates, the remaining coefficients were updated via the same three methods. Comparison of the results indicates that exogenous determination of the largest coefficients does not change the methods' rankings while yielding substantial improvements in the forecasts. This paper was presented at the Forty-Sixth International Atlantic Economic Conference, Boston, MA, October 8–11, 1998.