If you ask me the question ”How many people live in your town?” I could give you a correct answer being 5,000 % besides what you are looking for.
I live in Greve Municipality in Denmark. Population close to 48,000. Greve is a suburb south of Copenhagen. According to Wikipedia Copenhagen urban area has a population of 1.2 million and Copenhagen metro area has a population of 1.9 million people.
The Copenhagen metro area stretches from 40 km (20 miles) south of the city to 40 km (20 miles) north at Elsinore and Kronborg Castle (immortalized in Shakespeare’s Hamlet – always remember to include Shakespeare in a blog).
Further more: From Copenhagen you can look across the water to the east seeing Sweden and the city Malmoe. The Copenhagen-Malmoe bi-national urban agglomeration has a total population of 2.5 million people.
The real data quality issue in my initial question is not the precision, validity and timeliness in the number given in the answer but the shared understanding of the label attached to the number.
I noticed that Wikipedia has developed a good metadata habit when stating town populations giving 3 distinct labels: City, Urban and Metro.