It is not easy as it seems.

Letter to the Editor: Debatable assumption. Linda M. Austin, Stillwater. Roger D. Williams ("Better Figures," Aug. 20) cites the "frightening conclusions" of the president's tax plan revealed in a recent analysis by the accounting firm Ernst & Young. I just want to point out that all studies of this sort involve more than number-crunching; they are based on certain non-numerical assumptions. In this case, Ernst & Young has assumed that owners of large corporations create jobs and that any increase of their tax liabilities will result in declines in U.S. output, employment, capital stock, and investment. This is a debatable assumption generally known as the "trickle-down theory. It's a theory, not an incontrovertible fact, and in using it to generate their figures, Ernst & Young shows that it certainly has "a dog in the fight. To put it as neutrally and simply as possible, no number-crunching exists in a mathematical vacuum; it requires certain theories about the way the economy works. In this case, the connection between tax benefits for the wealthiest Americans and job creation is the theory underlying the numbers, not the fact resulting from the numbers. Many of the wealthiest Americans, like Mitt Romney, have made their money primarily through investments, buyouts, mergers and hedging. These strategies may have involved starting businesses and increasing production, or they may have involved closing businesses and firing people. But they are business practices that have no consistent or verifiable statistical connection to employment or productivity. Letters to the editor are encouraged.