3 MONEY makes the value of money change has become the duty of all who think themselves capable of expressing useful opinions on economic affairs. The following pages embody an attempt to assist in this task. They do not profess to be exhaustive : investigation of the past and discussion of schemes for the future have both been sacrificed in order that space might be zained for treatment of the present. S$ 2. Recognition and measurement of changes in the value of money. A great many attempts have been made to define money in few words. They have failed like similar attempts to define other economic terms commonly used in ordinary language. They fail because money, like most of the other great economic terms, and like nearly all words in common use, means different things in different contexts. In a context like the present, which suggests an investigation into the causes of rising and falling prices, it means the unit of account commonly used in purchases and sales and other commercial transactions. In the United Kingdom, Australia and South Africa, people buy goods with and sell them for pounds, shillings and pence, and “ prices” are always ex- pressed in quantities of these units: in the United States and Canada dollars and cents are used for the purpose : in France, francs and centimes : in India rupees, annas and pice. But as the cent and centime are merely decimal fractions of the dollar and franc, and the shilling and penny merely vulgar fractions of the pound, and annas and pice the same of the rupee, we can say for short and without any risk of being misunderstood, that the unit of account in these countries is the pound, the dollar, the franc, and the rupee. When, then, it is said in England that the value of money has fallen, what is meant is that