Final answer:
A decrease in capital stock will not produce an outward shift of the production possibilities curve.
Step-by-step explanation:
An outward shift of the production possibilities curve represents an increase in the economy's productive capacity. Among the given options, a decrease in capital stock (choice 3) will not produce an outward shift. When capital stock decreases, the economy's ability to produce goods and services is reduced, leading to a inward shift or a movement along the production possibilities curve.