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CPS2192 Laurent D. et al.
                                
                                               2
                                           ̅
            (10)         ̃ = ∑ ∑ (( ,  )) .
                                       ̃
                                           ̃
                        
                                            •
                                        
                            =1  =1

                 As  the  expressions  (8),  (9)  and  (10)  are  now  crisp,  the  well-known
            decomposition of the sum of squares can be easily verified:
                                        ̃ =  ̃ +  ̃ .
                                          
                                                           
                                                    
            and it follows that we can, analogously to the classical ANOVA case, derive a
                                                                        ͠  /(−1)
            test statistic. Let    be such a crisp test statistic, where  =   ͠  /(−)  .
                             
                                                                   
            Under the classical assumption of normality, we have   ~ −1,− .
                                                                  

            4.   Empirical analysis
                The 2014 SILC data represents more or less 17,000 persons from a sample
            of Swiss households. We take a subset of the database and keep only the
            active population, i.e. employed persons which age greater or equal to 18. We
            focus  our  analysis  on  the  financial  situation  with  a  poverty  attribute
            consisting of the two sub-items "good deprivation" and "satisfaction". These
            are of course only a part of the components of a multidimensional poverty
            measure. The table 1 describe our variables.

            4.1 Individual and global assessments
                After modelling each of these sub-items by triangular fuzzy numbers, and
            combining  them  by  aggregation  rules,  we  defuzzified  the  obtained
            aggregated  result  by  the  signed  distance  measure,  and  proceeded  to  the
            computation of the individual and global assessments. The distribution of the
            (crisp)  financial  situation  (finance)  is  sketched  in  figure  1.  The  global
            assessment, in this case the mean, is equal to 8.587. It is a relatively high value,
            which means a weak level of poverty according to finance. This measure is
            8.668 for the Swiss citizens and 8.099 for the foreigners, i.e. a sightly lesser
            (bad)  value  for  the  foreigners.  As  the  distribution  is  crisp,  we  can  without
            problem  perform  traditional  analysis  with  it.  For  instance,  a  T-test  of  the
            difference between the latter two global assesments (Swiss vs. Foreigners) can
            be  done  without  other  restrictions.  In  the  particular  case,  we  observe  a
            significant difference in global assessment of the financial situation between
            the two sub-populations.

            4.2 Fuzzy ANOVA
                We propose to execute a fuzzy ANOVA in order to test in a fuzzy context
            the  factor  foreign  on  the  two  sub-items  deprivation  and  satisfaction.
            Membership functions for these two latter variables have to be defined. We
            opted for triangular isosceles fuzzy numbers (Table 2). The results are listed in
            table 3 and show significant differences with respect to the factor foreign.

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