Mercer, one of the world's largest HR consultancy firms, releases its "Quality of Living Index" annually, which looks at cities that provide the best quality of life.

It's a way of helping multinational companies compensate employees fairly when placing them on international assignments, according to Mercer.

Looking at 450 cities across the world, Mercer takes into account the following metrics to judge which cities made the list for the best quality of life:

Political and social environment (political stability, crime, law enforcement).

Economic environment (currency-exchange regulations, banking services).

Socio-cultural environment (media availability and censorship, limitations on personal freedom).

Medical and health considerations (medical supplies and services, infectious diseases, sewage, waste disposal, air pollution).

Schools and education (standards and availability of international schools).

Public services and transportation (electricity, water, public transportation, traffic congestion).

Recreation (restaurants, theatres, cinemas, sports, and leisure).

Consumer goods (availability of food/daily consumption items, cars).

Housing (rental housing, household appliances, furniture, maintenance services).

Natural environment (climate, record of natural disasters).

Mercer made a list of 230 countries, and Business Insider took a look at the top 27 in the world. And no, New York and London did not make the cut.