Why a currency symbol removed raises spending

Two menus, identical dishes, identical numbers. One prints £18.00 and the other prints 18. Spend per head is reliably higher on the second. Nothing was hidden, nothing was discounted, and the diner could not tell you what was different about the page they read.

What everyone sees

Dropping the symbol looks like typographic minimalism, and is often defended that way by designers who chose it for balance on the page. Whatever the motive, the effect is not aesthetic. The symbol is the element that marks the number as money leaving the reader, and removing it removes the cue that triggers the felt cost.

What is actually happening

Prelec and Loewenstein described the pain of paying as a real disutility attached to the act of payment and distinct from the amount, which is why payment mechanisms that make the transfer less salient increase willingness to spend. Raghubir and Srivastava demonstrated the effect experimentally, finding that spending rose when payment felt decoupled or when the currency form was unfamiliar, with the same nominal cost producing different behaviour depending on how it was represented. Yang, Kimes and Sessarego tested menu price presentation in restaurants and found numeral-only prices associated with higher spend than prices with currency symbols or with a currency word. The design decision is therefore a pricing decision, executed in typography and recorded nowhere as a price change.

Why it stays hidden

The mechanism hides because the arithmetic is untouched. Anyone auditing the menu would find every price accurate and every total correct, so there is nothing to catch. The intervention operates on whether the number is processed as an outgoing payment at all, and that classification is not visible in any figure on the page.