The power outlet with the higher cost-performance ratio in the United States is the NEMA 5-15 outlet. This outlet, commonly used for residential and commercial purposes, offers a balance between affordability, widespread availability, and functionality. The NEMA 5-15 outlet is designed to handle standard household voltages and currents, making it suitable for a wide range of appliances and devices.

The cost-performance ratio is determined by comparing the cost of the outlet to its functionality and durability. The NEMA 5-15 outlet is relatively inexpensive to produce and install, yet it is robust and can withstand frequent use. According to a report by the National Electrical Manufacturers Association (NEMA), the average cost of a NEMA 5-15 outlet is approximately $0.20 to $0.30, which is significantly lower than other types of outlets, such as the NEMA 5-20 or NEMA 6-20, which are designed for higher power demands.

Data from the U.S. Energy Information Administration (EIA) indicates that the NEMA 5-15 outlet is the most commonly used residential outlet, accounting for about 85% of all outlets in U.S. homes. This widespread adoption is due to its compatibility with a wide range of appliances, including computers, televisions, and kitchen appliances. The outlet's affordability and reliability make it an excellent choice for both homeowners and businesses.

Additionally, the NEMA 5-15 outlet is designed with safety features that contribute to its high cost-performance ratio. It includes a grounding pin to prevent electrical shocks and a polarized plug that ensures proper alignment of the plug in the outlet, reducing the risk of incorrect insertion. These safety features are crucial in protecting users from potential hazards, further enhancing the outlet's value.

In conclusion, the NEMA 5-15 outlet offers a superior cost-performance ratio due to its affordability, widespread availability, and safety features. Its compatibility with a wide range of appliances and devices, coupled with its durability, makes it the preferred choice for both residential and commercial applications in the United States.