Final answer:
An economic life refers to the expected useful period of an asset, while a patent grants exclusive rights to an inventor. The question deals with Paper Mate's estimation of the economic life of their golden ink pen, which must be distinguished from patent duration.
Step-by-step explanation:
The question concerns the economic life and patent duration of a product by Paper Mate. When considering the remaining economic life and the patent expiration times, it's important to remember that these are two distinct considerations. An economic life is the estimated period during which an asset is expected to be economically useful to an owner, whereas a patent provides exclusive rights to an inventor for a fixed period of time, which is often 20 years in the United States. The question suggests that Paper Mate is working with a 21-year patent period and estimating that their exclusive golden ink pen's market relevancy will differ from the length of patent protection.
The specific answer concerning Paper Mate's estimation of the pen's remaining economic life is not provided in the text since it concerns proprietary company data that would not be available in general educational materials.