Editing Systemic risk (section)

====Pair/vine copulas====
A [[vine copula]] can be used to model systemic risk across a portfolio of financial assets.  One methodology is to apply the Clayton Canonical Vine Copula to model asset pairs in the vine structure framework.  As a Clayton copula is used, the greater the degree of asymmetric (i.e., left tail) dependence, the higher the Clayton copula parameter.  Therefore, one can sum up all the Clayton Copula parameters, and the higher the sum of these parameters, the greater the impending likelihood of systemic risk. This methodology has been found to detect spikes in the US equities markets in the last four decades capturing the Oil Crisis and Energy Crisis of the 1970s, Black Monday and the Gulf War in the 1980s, the Russian Default/LTCM crisis of the 1990s, and the Technology Bubble and Lehman Default in the 2000s.<ref>{{Cite journal|last=Low|first=Rand |date=2017-05-11|title=Vine copulas: modelling systemic risk and enhancing higher-moment portfolio optimisation.|journal=Accounting & Finance|volume=58 |pages=423–463|doi=10.1111/acfi.12274 |issn=1467-629X|doi-access=free}}</ref> Manzo and Picca<ref>{{cite journal|last1=Manzo|first1=Gerardo|last2=Picca|first2=Antonio|title=The Impact of Sovereign Shocks|year=2018|journal=Management Science, Forthcoming|ssrn=2524991}}</ref> introduce the t-Student Distress Insurance Premium (tDIP), a copula-based method that measures systemic risk as the expected tail loss on a credit portfolio of entities, in order to quantify sovereign as well as financial systemic risk in Europe.