a. National income accountants compare the market value of the total outputs in various years rather than actual physical volumes of production because multiple choice 1 there is better information about the market value of the total outputs than the actual output level. it is impossible to summarize two different goods, say, oranges and computers, as a single statistic. national income accountants only receive information on the market value of the total outputs. the percentages of the market value and actual production volumes could never be the same. b. Comparing market values over time has the multiple choice 2 benefit of providing information for trend analysis. advantage that prices change over time. simplicity of a single measure. disadvantage that prices change over time.