A visitor drinks beer on the first day of the 182nd Oktoberfest in Munich, Germany, September 19, 2015. Reuters Every year Mercer, one of the world's largest HR consultancy firms, releases its Quality of Living Index, which looks at which cities provide the best quality of life.

The ranking is one of the most comprehensive of its kind and is carried out annually to help multinational companies and other employers to 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 23 in the world. And no, New York and London did not make the cut.