m-Quotient (Hirsch m)

The m-quotient, defined by Jorge Hirsch in the same 2005 paper that introduced the h-index, normalizes an author's h-index by the length of their scientific career. Because the h-index can only grow over time and never decreases, raw h-values systematically favor senior researchers and make it unfair to compare early-career scientists with established ones. The m-quotient divides the h-index by the number of years since the researcher's first publication, yielding a rate of impact accumulation per year. Hirsch proposed rough benchmarks on this scale, suggesting that a sustained value near 1 characterizes a successful scientist, near 2 an outstanding one, and near 3 a truly exceptional figure, making the m-quotient a tool for comparing researchers at different career stages.