Final answer:
If Loblaw effectively replaces print flyers with online advertising and increases market expenditure, the average total cost could decrease, and economic profit may potentially increase, depending on the effectiveness of the online marketing strategy.
Step-by-step explanation:
When Loblaw decides to pull its flyers and shift towards online advertising while increasing its market expenditure, it impacts its cost and revenue curves, and consequently, its economic profit. The company might experience a decrease in its average total cost (ATC) at the profit-maximizing output if it can reduce marketing costs by transitioning to more cost-effective digital means. If online advertising is effective at driving sales, then the revenue may remain stable or even increase. Therefore, economic profit can either increase if the reduction in costs outpaces any potential loss in revenue or decrease if the opposite occurs.