Abstract：
The paper studies seasonality of conceptions among five distinct population subgroups of mainland Greece for the period 1951-2002. The populations explored include those residing in Metsovo, Dion, Organi, Kehros, as well as a \"General\" Sample consisting of persons located in various areas of continental Greece. The populations under investigation present diverse characteristics regarding religion, cultural background, socio-economic status etc. Records of births were derived from the Vital Registration System of the respective municipalities and communities of the populations under research were constructed. The date of child conception was estimated as the recorded date of birth minus 260 days.The analysis focuses, among others, on the construction of seasonal indices, applying a variant ratio to moving averages method which reveal, in relative terms, the seasonality of the phenomenon. Subsequently, these ratios are considered as the dependent variable in regression models while months, expressed in terms of dummy variables, are introduced as predictors. Four main sub-periods are considered; 1951-64, 1965-80, 1981-92 and 1992-2002. The findings show that the extent of seasonality differs between periods as well as between the five population subgroups though the phenomenon becomes less prominent over time in all cases. There is a tendency of an increased number of conceptions among mountainous populations during summer, irrespective of religion or socio-economic status, possibly partly due to environmental factors (i.e. seasonal workload, domestic organisation of extended families, etc). Nevertheless, the mountainous populations differ regarding the intensity and duration of this phenomenon. By contrast, in Dion, a lowland Christian Orthodox population, conceptions increase after Easter and remain elevated until June.
摘要：
本文研究了1951-2002年期间希腊大陆五个不同人口亚组之间概念的季节性。探索的人口包括居住在Metsovo的人口，迪翁,Organi,Kehros,以及由位于希腊大陆不同地区的人员组成的“一般”样本。被调查的人群在宗教方面表现出不同的特征，文化背景,社会经济地位等。出生记录来自各市的生命登记系统，并建立了正在研究的人口社区。儿童受孕日期估计为记录的出生日期减去260天。分析的重点,其中,关于季节性指数的构建，将变体比率应用于移动平均线方法，相对而言，现象的季节性。随后，这些比率被认为是回归模型中的因变量，而月份，用虚拟变量表示，被介绍为预测因子。考虑了四个主要的子时期：1951-64年，1965-80年，1981-92年和1992-2002年。研究结果表明，季节性的程度在各个时期以及五个人口亚组之间都有所不同，尽管在所有情况下，这种现象都随着时间的推移而变得不那么明显。夏季山区人口中的概念数量有增加的趋势，无论宗教或社会经济地位如何，可能部分是由于环境因素(即季节性工作量，大家庭的家庭组织，etc).然而，山区人口在这种现象的强度和持续时间方面有所不同。相比之下,在迪翁,低地基督教东正教徒，概念在复活节后增加，并一直持续到6月。
