Which of the following would be an example of economic or external obsolescence?

Economic or external obsolescence refers to a loss in property value caused by external factors that are typically outside the control of the property owner. Among the choices provided, the example of a poor floor plan does not fall under economic or external obsolescence, as it concerns the internal characteristics of the property itself—those that can often be modified or improved.

In contrast, options like changing land uses in a neighborhood, the major employer in the city going out of business, and nearby contamination from a landfill all illustrate factors that originate outside the property and impact its desirability and, consequently, its market value.

For instance, when a major employer leaves a city, it can lead to a decrease in demand for housing and commercial spaces in the vicinity, affecting property values negatively. Similarly, changing land uses can alter the character of a neighborhood, making it less attractive to potential buyers or tenants. Lastly, the presence of pollution or contamination from a landfill can pose health risks or lower the aesthetic appeal of the area, leading to a decline in property values.

Overall, the correct choice highlights a factor that diminishes value due to external influences rather than due to the property's internal characteristics.