Current theories on economic growth are stressing the important role of creativity and innovation as a main driver of regional development. Some perspectives, like Richard Florida's "creative class theory", have elected tolerance and diversity as a core concept in explaining differential development between different places, but his assumptions are challenged by other empirical and theoretical studies. In this article, we raise the possibility that tolerance is a necessary yet not a sufficient ingredient to trigger economic development in regions, and explore the role of subjective well-being (life-satisfaction, happiness, and optimism) as a moderator. Using a nationwide survey of 3,757 respondents from 21 different municipalities, the results show that optimism played the role of moderator, thus evidencing that psychological variables should be taken into account when trying to understand regional economic development.