The government, in the above example, may still want tax revenue for the net income, even if the farmer builds the table himself. But imputed income is difficult to identify and very difficult to tax. Hence, the farmer—and any person or business with the requisite internal resources—could avoid or evade income or sales taxation associated with imputed income, and thus shift liability for the cost of government to others who engage—or have to engage—in interpersonal or inter-business trade. Smaller businesses, which are highly adaptable but have fewer internal resources than larger businesses, may be disproportionately impacted from imputed income activity under an income or sales tax.
All taxes can impact trade and sales prices, but sales and income taxes are perpetual (continue to occur even when revenue requirements have been met) and can, especially at higher tax rates, discourage trade and economic efficiency usually associated with the division of labor.