This
picture of the various sizes of quality street tins over the decades seems to have gone viral, with everybody glad to see what they knew all
along - that our products are smaller than they used to be. The term for this
in economics is called 'shrinkflation'. This is where sellers surreptitiously
reduce the size of their goods (the mass of a chocolate, the size of the tin,
etc) as a way to put up the price of their goods while appearing to be
competitive.
In other
words, there are two ways to increase prices of goods of variable size and
quantity - you can do it the transparent way by adding a sum on to the original
price, or you can retain the original price and reduce the mass of the product.
That is what is happening with those tins of Quality Street - the unit cost is
increasing but at a rate whereby the purchase price, relative to former
purchase prices, has not shifted in a way that puts off price sensitive
consumers.
