Give an example of two variables which have no direct causal

Give an example of two variables which have no direct causal connection, yet it is reasonable to expect that they are highly correlated. Justify your answer.

Solution

A spurious relationship occurs when two variables are related and appear to have a direct causal connection. For example there is really no direct causal relationship between number of storks and births. Instead both the number of stroks and the number of births are dependent variables, influenced by the same independent variable, rurality of the area, with more rural areas having fewer people and feer nesting places for storks such as chimneys and houses.

A highly correlation is one in which the two correlated variables are very closely related: as one variable changes, the other variable changes right along with it in many cases. When two variables are strongly correlated, we are better able to make accurate predictions about specific individuals. That is, if an individual has a particular value of one variable, that individual is very likely to fall within a small range of values with regard to the correlated variable.