Final answer:
According to surveys of subjective well-being, the two countries with the highest levels of self-reported happiness are Denmark and Switzerland.
Step-by-step explanation:
The two countries with the highest levels of self-reported happiness, according to surveys of subjective well-being, are Denmark and Switzerland. These findings are based on various studies and reports, such as the World Happiness Report and research by Diener et al. (1995, 2010).