That's very interesting. In the car driving example we can define three variables: 1) Throttle 2) Speed 3) Elevation derivative If "3" is constant (ex: flat te

That's very interesting. In the car driving example we can define three variables: 1) Throttle 2) Speed 3) Elevation derivative If "3" is constant (ex: flat terrain) then "1" and "2" will have strong correlation. However if "2" is constant (ex: cruise control) as in your example, "1" and "3" will have strong correlation. In the economic example, however, this kind of analisys should be much more complex and take plenty of variables into account.