Arthashastra stipulates restraint on taxes imposed, fairness, the amounts and how tax increases should be implemented. Further, state Waldauer et al., the text suggests that the tax should be "convenient to pay, easy to calculate, inexpensive to administer, equitable and non-distortive, and not inhibit growth. Fair taxes build popular support for the king, states the text, and some manufacturers and artisans, such as those of textiles, were subject to a flat tax. The Arthashastra states that taxes should only be collected from ripened economic activity, and should not be collected from early, unripe stages of economic activity. Historian of economic thought Joseph Spengler notes: