Thread by @arthurturrell

Today, @ONS & @DataSciCampus publish an article tracking the prices of the lowest-cost grocery items using web-scraping, inspired by @BootstrapCook & other campaigners who have rightly asked about the #costofliving experiences of the poorest in society. Here's what we found 🧵

First: a caveat. This is highly experimental research, as web-scraping supermarket data for 30 grocery items can go wrong in multiple ways! But even though this is experimental, we thought it was really important to talk about it and the results. 2/n
#datascience #econtwitter

Okay: results. Lowest cost items (eg value brands) have had significant price increases: 13 of 30 monitored had average lowest price increase faster than overall equiv. inflation measure. Big movers: pasta (up 50%), crisps (17%), bread (16%), minced beef (16%) & rice (15%). 3/n

But not everything is getting more expensive! For 6 of the 30 items, the lowest prices fell on average over the 12 months to April 2022. Price decreases were measured for potatoes (a 14% fall in price), cheese (7%), pizza (4%), chips (3%), sausages (3%) and apples (1%). 4/n

For those on low incomes, what also matters is the absolute price change in £ and p. So we included this table showing the price movements in pence and you can see that beef mince leads the table. 5/n

One interesting finding from this research is that the difference between the lowest cost grocery item & the next lowest cost grocery item (which you might buy if the value brand becomes unavailable) is quite large: for over two-thirds of the items, it was 20% more expensive. 6/n

So what's the big picture? We've done our best to create a combined measure of the price changes of these lowest-cost grocery items. Overall story: prices for the lowest-cost items increased at a similar rate to the equivalent official measure of inflation for food and drink. 7/n

Huge shout out to ppl in @ONS @DataSciCampus, Prices, Methodology, & Comms for doing this hugely relevant & innovative work on #costofliving (inspired by @BootstrapCook & others). Truly, #datascience for the public good. Find more about our work here: datasciencecampus.ons.gov.uk END