Sibuya’s Dependence Function: a Copula Alternative Nikolai Kolev 1 , Marcelo Goncalves 1 and Boyan Dimitrov 2 1 Department of Statistics, University of Sao Paulo, Brazil 2 Science and Math. Department, Kettering University, USA. nkolev@ime.usp.br, mgonca@ime.usp.br and bdimitro@kettering.edu