A livability index would be nice, to make it clearer.

You could chop it up into various bits. In no particular order:

Costs
a) Food, water, electricity prices as % of median net hourly wage.
b) Median home prices, include quality of housing

Comfort
c) Safety and good governance (Corruption perceptions index,
d) % of roads that have dedicated, interconnected pedestrian and bicycle paths
e) % of city interconnectively covered by public transit (density, frequency, punctuality, comfort)
f) % of cityspace dedicated to green space (trees, parks, etc.)

and so on, and so on.