Question

The number of cars in a number of cities shows a positive correlation to the population of the respective city. Can it be inferred that an increase of cars in a city leads to an increase in the population?

Answer 1

Answer: No

A correlation is a relationship between two variables that tend to move in the same direction. Therefore, a positive correlation will describe two variables that increase together. However, correlation does not always equal causation, and in this case, this conclusion cannot be made. A more probable explanation is that there is some third variable causing an increase in population, so more people are buying more cars, not the other way around.