Engineers do engineering, i.e. they build bridges. So engineering needs engineers. The economy does NOT need economists. Economists do not make economy, but they try it and that is why we have so much problems with some financial models.
Economics is too important to leave to the economists.
If you have a sane economy, and by sane economy I mean one which is not addicted to debt, not a Ponzi economy, then the change in debt each year should contribute a minor amount to demand. Therefore, if you tried to correlate debt to the level of unemployment you would not find much of a correlation. Unfortunately that is not the economy we live in.