Final answer:
The assertion that plant asset additions and improvements are expensed when incurred is false; they are capitalized and depreciated over time to match their prolonged benefit.
Step-by-step explanation:
The statement 'Additions and improvements to a plant asset that increase the asset's operating efficiency, productive capacity, or expected useful life are generally expensed in the period incurred' is false. These types of costs are not merely expensed but are capitalized, meaning they are added to the asset's value on the balance sheet and depreciated over the useful life of the improvements.
Capitalizing such expenses acknowledges that their benefit extends over multiple periods, aligning the cost with the increased profits or efficiencies the improvement brings. Firms engage in investment strategies, such as purchasing new equipment or expanding facilities, with the expectation of generating future profits.