Four Boston-area residents — a celebrated novelist, a Harvard economist, a pediatric neurosurgeon, and a man who carves, shapes, and threads some of the world’s most finely crafted instrument bows — are among 23 people worldwide chosen to be the 2012 MacArthur Fellows and recipients of the foundation’s “genius grants.”

The grants, disclosed Monday, are awarded annually based on nominations by those considered to be at the top of their fields. Recipients, chosen for their intense dedication and unique approaches to their professions, each receive $500,000 from the Chicago foundation.