The price of stamps is always an interesting proxy for inflation, and this article reveals that had stamps tracked inflation since 1989, a first class stamp should cost 41p not the 67p that it now does.

However, the reason this is 'Microeconomic' is because I'd like to unpick what might be behind the price increases. A rise in price, elementary microeconomic principles tell us would come about either because of an increase in demand or a reduction in supply. However, has there been an increase in demand? You wouldn't have thought so - the number of letters sent has decreased, although online retail has increased the number of parcels sent. Thus, are the former subsidising the latter?

Alternatively, have costs risen? This seems more likely - the unit cost of delivering a letter is likely to have risen, particularly if the Royal Mail has been unable to drive down costs, notably labour costs. And yet, you would have thought that the threat of competition, not least in the parcels sector, would have put downwards pressure on prices as well as the rising number of competitors. So, is this sort of rate of price increase sustainable?