It is pointed out that the powerful statistical methods introduced by Bachelier and Mandelbrot in Economics, and those introduced by Hurst and Feder in Marine Sciences, can be readily used to examine fluctuation phenomena in hadron-production processes. Evidences for the existence of non-Gaussian stable, stationary, scale invariant distributions, fractal dimensions, and the validity of Hurst's empirical law are presented. Since none of the observed features is directly related to the basis of the conventional physical picture, it is not clear whether (and if yes, how and why) these striking empirical regularities can be understood in the framework of the conventional picture including QCD.

PACS numbers: 13.85.Tp, 05.40.--a, 13.85.Hd