Why do tax reformers keep repeating "broad base, low rate, simple rules"?

A Gujarat tax tribunal once had to rule on what a paratha is. A plain roti was taxed at 5%; a frozen paratha, the bench decided, must be heated before it can be eaten, which made it a different food—taxable at 18% (India.com). Firms and the tax department argued it in earnest, because real money rode on which bread it was. That small absurdity is what “broad base, low rate, simple rules” exists to prevent, and every departure from the rule sends a bill somewhere else.

The moment two similar things are taxed differently, someone has to draw the line between them—and the paratha shows how blurry that line can be. A firm redesigns its product to fall on the cheaper side; the tax office disputes where it lands; both spend real effort producing nothing. The more slabs and exceptions a tax carries, the more such lines there are to police, and the more paperwork it takes to prove which side of each you sit on—a cost that falls hardest on the small firms least able to bear it.

Carve-outs have an unseen cost as well; a narrow base pushes up the rate on everything else. The revenue a government forgoes by exempting food, or taxing it lightly, has to be raised from whatever is left. India’s own task force designing GST warned, back in 2009, that exempting broad categories like food could shrink the base so far that the standard rate would have to be “substantially higher.” And once it climbs, the next industry lines up to be declared an “essential” too.

An exemption is not even the gift it appears to be. A seller that charges no GST on its sale still pays GST on its rent, equipment and hired services; unable to reclaim that, it buries the tax in its price (see “If something is GST-exempt, why isn’t it cheaper?”). The carve-out meant to make something cheaper ends up taxing its production instead.

So the mantra is really a warning that has been worn smooth by repetition. A broad base keeps the rate low; a low rate dulls the urge to cheat or reclassify; simple rules leave less to fight over. Each concession of this dictum looks trivial on its own—one exemption, one softer slab—but the costs add up and the GST stops being the clean, cheap tax it was sold as.