I am the Vice President of Programs at the Luminos Fund where I oversees the global programs team to support joyful, foundational learning for children at the margins. I started out as a medical researcher before embarking on a career in evidence-informed decision making within the International Development sector. I have specialised in education - and specifically in foundational learning - because I am convinced that solving the learning crisis could lead to truly transformational change.
Great paper - I love the approach of considering a broader range of impacts together.
On the impacts of schooling versus learning a good paper is https://riseprogramme.org/sites/default/files/2020-11/RISE_WP-049_Kaffenberger_Pritchett.pdf
Re. cost-effectiveness there are examples of very cost effective interventions - see analysis from @Vadim Albinsky above.