Which are the easiest and hardest parkruns in the UK?

Every weekend over 1.5 million people run 5,000m on Saturday mornings for parkrun which is a free event that takes place all over the UK and indeed across the globe. Each runner is given a bar code, which is scanned at the end of the run and fed into a database showing them what place they came in their race. Jordan Dunbar and Tim Harford take a look at which courses are the fastest, slowest, hardest and easiest.

First broadcast on More or Less, 4 February 2018.