@article{eprints706,
            year = {2008},
           title = {Threshold copulas and positive dependence},
           pages = {2902 -- 2909},
          number = {17},
          author = {Fabrizio Durante and Rachele Foschi and Fabio Spizzichino},
         journal = {Statistics \& Probability Letters},
          volume = {78},
        abstract = {Starting with a notion of positive dependence View the MathML source and with the family of the lower threshold copulas Ct associated with a bivariate distribution having copula C, we define different notions of positive dependence for C, reflecting the dependence properties of the copulas Ct for some t.
Then, we analyze some structural aspects of lower threshold copulas and of the given definitions. Furthermore we consider several specific cases arising from relevant special choices of View the MathML source (e.g., PQD, LTD, TP2 and PLR). Our analysis, in particular, allows us to present a number of relevant examples and counter-examples, which can be useful in the study of the tail dependence for a bivariate distribution.},
             url = {http://eprints.imtlucca.it/706/}
}