From a young age, Fletcher wrote reports on social and health issues.[2] These included one on child employment in lead mines, for the Children's Employment Commission 1842.[3] His commission reports influenced legislation. The findings of the children's employment commission in particular laid the basis for parliamentary control. As a schools inspector he wrote also on education.[2]
In 1850 Fletcher published a Summary of the Moral Statistics of England and Wales; and in the following year a work on Education: National, Voluntary, and Free.[2] He was unconvinced of the moral superiority of communities that were relatively sparsely developed, such as small towns and farming areas, presaging views later held by Herbert Spencer and Norbert Elias.[4] He studied foreign educational systems, and issued (1851–2) two treatises on The Farm School of the Continent, and its Applicability to the Preventive and Reformatory Education of Pauper and Criminal Children in England and Wales.[2]