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International Journal of
            Population Studies                                         Gender gap in life expectancy in South and East Europe



            acquired by inversion of the consistent estimator of the               E(   )            (8)
                                                                                          ,
            variance-covariance matrix of the moment conditions. As            tj  tj   it,  it j,
            further stated by Wooldridge (2001a), if there are m > k + 1
            total moment conditions, where, k represents the number of   Where,  m is the test statistics of  j-th order of serial
                                                                          j
            covariates in the model, the weighting matrix would have m   correlation and ρ  is the average j-th order auto-covariance.
                                                                            j
            × m dimensions. In addition, if concerns are existed about   3. Results
            heteroskedasticity, there are methods for calculating standard
            errors and testing statistics that are robust to heteroskedasticity   3.1. Trends of the gender gap in LEAB in South and
            of not known form. The usual approach when facing   East European countries
            heteroskedasticity of unknown form is to use the GMM   Solid evidence has shown that a spectacular rise in LEAB
            (Baum  et  al., 2003). The GMM estimator using weighting   for South and East European countries that started
            matrix places no restrictions on either the unconditional   since 1965 has continued to progress and some of South
            or conditional (on  Z) variance matrix of  u, that is, the   European countries (e.g., Spain, Italy, Malta, Portugal, and
                                                i
                             i
            asymptotically efficient estimator can be obtained without   Cyprus) are now the leaders of LEAB in Europe (Caselli
            making additional assumptions (Wooldridge, 2001b). First,   et al., 2014; Eurostat, 2021; United Nations, 2022a).
            differencing is applied to remove the unobserved effect, and
            thereafter, lags are utilized as instrumental variables for the   Figure 1A and 1B presents LEAB levels and the gender
            differenced lagged dependent variable. Wooldridge (2001a)   gaps in LEAB for 24 countries in the study region. The figures
            added further that since the original time-varying errors   show that the group of South and East European countries
            are supposed to be serially uncorrelated, the differenced   is heterogeneous in different levels of LEAB. In general,
            errors must have serial correlation. GMM is well fitted for   LEAB for both sexes is lower for Russia, Ukraine, Belarus,
            securing efficient estimators that consider for the serial   Moldova, Türkiye, Bulgaria, Romania,  Montenegro,
            correlation (e.g., Arellano and Bond (1991). As specified by   Bosnia and Herzegovina, Macedonia, Serbia, and
            Lucas et al. (1997), the approach of Arellano and Bond (1991)   Hungary,  whereas it is higher in Italy, Portugal, Spain,
            supports consistent estimates under very weak distributional   Malta,  Cyprus,  Greece,  and  Slovenia.  The  group  of
            assumptions. Developed by Arellano and Bond (1991),   countries as Albania, Croatia, Czechia, Slovakia, and
            GMM techniques can control for both unobserved country-  Poland is more or less in an intermediate position. In
            specific effects and first difference non-stationary variables,   South Europe, not only the gains in LEAB in the period
            and further to overcome the problem with endogeneity of   1991 – 2020 vary greatly but geographical inequalities are
            the explanatory variables using instruments and test for the   more pronounced than elsewhere. During the period of
            presence of autocorrelation (Adusei, 2013). For dynamic   our research study (1991 – 2020), Türkiye, Croatia, and
            model estimation using yearly data, it is found that GMM with   Malta are the three countries where the expected LEAB
            additional moment conditions can provide more accurate   increased the most (by 9.5, 8.1, and 7.8 years, respectively),
            estimates than two-stage least squares (Wooldridge, 2001a).  unlike Montenegro and Bulgaria, where the increase was
                                                               only 0.5 years and 3.7 years, respectively.
              For models estimated by GMM, the first- and second-
            order serial correlation statistics initiated by Arellano   One characteristics of mortality in the study period
            and Bond (1991) were used as a method to test for serial   1991 – 2020 are the stagnation of LEAB in 1991 – 1995
            correlation. The test has in effect two different statistics,   due to the increase in probability of dying at almost all
            one for first-order correlation and the other for second-  age groups that were resulted from impacts of collapse
            order correlation. If the innovations are i.i.d., it is expected   of previous socioeconomic systems in these countries.
            the first-order statistic to be significant (with a negative   During the beginning of the 1990s, many East European
            autocorrelation coefficient), and the second-order statistic   countries even underwent decrease in LEAB, while other
            to be not significant (Arellano & Bond, 1991). The test   parts of Europe witnessed an increase (SORS, 1997). The
            statistics proposed by Arellano and Bond is calculated as   considerable increase of LEAB in the mid- or late-1990s
            shown in Eqs. (6-8):                               is probably the response of that earlier stagnation in
                                                               mortality trends that are generally attributed to an end of

                           m      j                    (6)    health crises of the transitional period. As Avdeev et al.
                            j
                                VAR  ()                       (2011)  stated,  across  Europe,  females  have  a  longer  life
                                      j
                                                               than  males,  but  the  range  of  the  gap in  LEAB  between
                                                               the two sexes varies extensively, as does the development
                                 1     T

                             T 3  j  t 4  j  tj  (7)    in the region throughout the time. Thus, South Europe
                            j
                                                               follows the same trend of East Europe but with greater
            Volume 7 Issue 2 (2021)                         21                     https://doi.org/10.36922/ijps.v7i2.389
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