The cost method could invite earnings manipulation because firms using it recognize dividend income as profit, even if the investment's value has changed. This inflates reported income and can lead to manager bonuses tied to those inflated figures.In contrast, the equity method adjusts the investment account based on the investee's performance, giving a more accurate reflection of value. The fair-value method reflects market conditions but may also affect manager incentives. Both offer greater transparency than the cost method, reducing the chance of unearned performance rewards.