The Office for National Statistics monitors inflation by using the Consumer Price Index, which uses a representative sample of consumer goods and services purchased by households.
The easiest way to think about this is to imagine a very large shopping basket full of goods and services which the ‘typical household’ buys on a regular basis – researchers from the ONS use already existing survey data to figure out which goods and services best reflect the nation’s consumption habits in 12 ‘expenditure categories’ such as ‘food’, ‘housing’ and ‘communication’ – and track the prices of these items over time to measure inflation, or changes to the cost of living for the ‘typical’ household.
For example, under ‘food’, the ONS monitors the prices of items such as chips, pastry-based snacks and raspberries, among other things, these items representing expenditure on ‘frozen potato products’, ‘savoury snacks’ and ‘soft fruit’.
Somewhat surprisingly, there’s all sorts of links in here to aspects of the Families and Households module!
The ONS updates the items in the ‘shopping basket’ every year to reflect trends in consumer spending – it removes items which have become significantly less popular and adds in new items.
The changes actually provide an entertaining insight into changes in lifestyles in the UK. For example, some of the changes made to the basket in 2019 included:
- Dinner plate replaced crockery set to reflect the fact that cutlery is more likely to be bought as single items (reflecting the shift to single person households)
- Non-leather settees replace three piece non-leather suite, reflecting the same trend as above.
- Portable speaker and smart-speaker replaced Hi-Fi, reflecting changes in technology.
- Bakeware – a new category – reflecting the fact that people have been watching too much Bake-Off.
- Popcorn – added – possibly reflecting the rise of stay at home movie watching.
- Dog Treats – replaced dry dog food – reflecting the increased importance of pets in family life (which kind of reminds me of the Personal Life Perspective!).
You might also like to read the methodology section of the ONS’ CPI, it’s an interesting one for sampling: in terms of how they choose the products, it’s not straightforward!