What happens if you pass backwards over a red line?
Yes, you increase income and reputation when passing backwards over it, and decrease them when passing forwards.

The rules are pretty simple:


  When a player's Population crosses a Red Line, then that player's Income and Reputation are both reduced by 1 (moved to the left one space) for every Red Line the player moves past. If a player's Population dips below a Red Line (this can happen if he has a negative reputation) he moves both his Income Cylinder and his Reputation Cube forward (moved to the right one space).