(Image: AAP/Paul Braven)

It's that time of year again. Last week The Economist's annual "global liveability index" named Melbourne and Sydney, respectively, the second and third most liveable cities in the world. Vienna took out the top spot.

However, one day earlier, these same cities were ranked only 23rd and 24th on a "generation Z liveability index", after last year placing 21st and 24th on the "best millennial cities index". Compiled by renting platform Nestpick, these studies determine which cities best match the values and interests of young people.