While proofreeding I noticed the following error I would like to...

While proofreeding I noticed the following error I would like to amend. The following statement:

Therefore, an increase in the price of copper will mean a higher ratio of increase in profits, and hence lower ratio of decrease of PE, for higher cost producers than lower cost producers.

should obviously have read:

Therefore, an increase in the price of copper will mean a higher ratio of increase in profits, and hence HIGHER ratio of decrease of PE, for higher cost producers than lower cost producers.

These double negatives sometimes give me a brain freeze heh heh.