The Austrian capital, Vienna, is known for its museums, palaces and ease of living. The city of 2 million people was recently identified as having the world's highest quality of life for the tenth year in a row. That opinion comes from Mercer, a consulting agency that does a yearly Quality of Living Ranking. Measuring quality of life is not a simple job. In a statement, Mercer said the agency looks at many factors. For example, researchers measure how easily people can use public transport, such as buses and trains. They ask whether drivers can move well on the roads. They ask if houses and apartments are available at a good price, and whether children can go to international schools. They think about whether people in the city can enjoy music, theater, restaurants and sports. And, they look for a healthy political and social climate.