ForecastdistributionhasbeenassumedGammainthemodelingprocess.WecouldalsoselectNon-parametrictocharttheforecastdistribution.
Nonparametricmethodsarestatisticalmethodsthatrequirefewerassumptionsaboutapopulationorprobabilitydistributionandareapplicable
inawiderrangeofsituations.
Table6showstheStandardDeviation(SD)oftheCDRsoverasequenceof1-yearviews,usingthesimulationresults.Noticethatthesimulation
resultsareveryclosetotheanalyticresultsinTable3.Table6isincrementalwhereasTable7iscumulative.AcomparisonwithTable4showsthat
thesquarerootofthesumofsquaresoftheCDRsareveryclosetothestandarddeviationsfrombootstrappingMack’smodeloverthelifetimeof
theliabilities,andagaindemonstrateshowthelifetimeviewofriskunderMack’smodelcanbepartitionedintoasequenceofone-yearviews.
[email protected]%oftheCDRsoverasequenceof1-yearviews,usingthesimulationresults.Again,this
highlightsthebenefitsofasimulationapproachsinceanyriskmeasurecanbeappliedtothesimulateddistribution.Theanalyticapproachonly
providesSDs.
ThevaluesinTables3and6showremarkablesimilarity,validatingthesimulationapproachesandconnectingthelifetimeandone-year
viewsofriskforanalyticandsimulation-basedapproachesassociatedwithMack’smodel.Again,anadvantageofthesimulation-based
approachisthatafullpredictivedistributionisavailable,fromwhichanyriskmeasurecanbeobtained.Forexample,Table8and9shows
valueat-riskoftheCDRsat99.5%(whereVaRat99.5%isthenegativeofthe0.5thpercentileofthedistributionoftheCDR).
Forastatisticalmethodtobeclassifiedasanonparametricmethod,itmustsatisfyoneofthefollowingconditions:(1)themethodisusedwith
qualitativedata,or(2)themethodisusedwithquantitativedatawhennoassumptioncanbemadeaboutthepopulationprobabilitydistribution.
Incaseswherebothparametricandnonparametricmethodsareapplicable,statisticiansusuallyrecommendusingparametricmethodsbecause
theytendtoprovidebetterprecision.Nonparametricmethodsareuseful,however,insituationswheretheassumptionsrequiredbyparametric
methodsappearquestionable.
Source:https://www.britannica.com/science/statistics/Residual-analysis
Summary Tables –Simulated CDR Method 3 Results
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