finance question

As with all economic predictions, they can only be assumptions.
The world's economy is always in flux, so mathematical formulas are useless.
What's available today in regards to any economy in the world can change based on many unpredictable factors.

That's why their assumptions usually include the phrase ceteris paribus.

That sounds too much like Greek to me! ;(

No one on this planet can predict income or growth of any company. It can be an assumption only.

It's Latin, of course. You can use Google, or just ask George.