Liar's Wednesday

Due to manufacturing limitations, all chocolate coins contain an equal mass of chocolate regardless of the dimensions of the finished coin. The size–weight illusion means this is rarely recognised by consumers.

This is absolute rubbish! The size of chocolate coins is directly linked to your currency’s exchange rate with that of Ecuador (sometimes called the Chocolate Standard).
Since the Dollarisation of the Ecuador economy in 2000 they are based on the Stirling/Dollar rate. Ecuador still mints low value coins but uses dollar notes.
In 2006 several London Merchant Banks paid their employees annual bonuses in chocolate coins to avoid income tax.