The Amoroso–Robinson relation, named after economists Luigi Amoroso and Joan Robinson, describes the relation between price, marginal revenue, and elasticity of demand.
∂R∂x=p(1+1ϵx,p){\displaystyle {\frac {\partial R}{\partial x}}=p\left(1+{\frac {1}{\epsilon _{x,p}}}\right)},
where