Final answer:
An appraiser indicating that a pool increases a property's net income refers to improvements raising the property's value more than their cost, called 'internalizing externalities' in economics lingo.
Step-by-step explanation:
When an appraiser suggests that the addition of a swimming pool will add to the net income of a property, they are referring to the concept that certain improvements can increase the property's value beyond the cost of those improvements. This can be understood in the context of economics lingo, where the term 'internalizing externalities' might come into play. Although in this specific scenario, the term more closely relates to capturing additional value or potential income not necessarily associated with externalities.
Essentially, the appraiser is implying that the pool could lead to higher property value or attractiveness to potential renters or buyers, thus increasing the overall income that can be derived from the property. This assessment by an appraiser can depend on various factors, including the desirability of pools in the market, the climate of the area, and the demographics of potential property users who might see a pool as a benefit.