Several studies show that a positive mood induces subjects to spend more of their time in more creative tasks.

Cons

Most experimental studies have been based on small numbers of subjects who were not incentivized to complete the tasks assigned to them in a laboratory setting.

Experimental laboratory evidence is based on student subjects and so is not representative of the working population.

Most studies based on real-world data have not been designed to demonstrate causality.

A minority of studies report small or even negative effects of positive emotion on productivity.