  We prove that the killing rate of certain degree-lowering "recursion
operators" on a polynomial algebra over a finite field grows slower than
linearly in the degree of the polynomial attacked. We also explain the
motivating application: obtaining a lower bound for the Krull dimension of a
local component of a big mod-p Hecke algebra in the genus-zero case. We sketch
the application for p=2 and p=3 in level one. The case p=2 was first
established in by Nicolas and Serre in 2012 using different methods.
