David J. Aldous, Antar Bandyopadhyay, A Survey of Max-Type Recursive Distributional Equations, The Annals of Applied Probability, Vol. 15, No. 2 (May, 2005), pp. 1047-1110 ...

In this article, we study some new characterizations of primitive recursive functions based on restricted forms of primitive recursion, improving the pioneering work of R. M. Robinson and M. D.

Recursion has more expressive power than iterative looping constructs. I say this because a while loop is equivalent to a tail recursive function and recursive functions need not be tail recursive.