Lone mothers are among the groups most affected by income poverty in Germany. Previous research shows that both lone mothers’ social composition (e.g. employment status, age, number of children) and the institutional context (e.g. family and labour market policies) are crucial for explaining this high vulnerability. Yet we know little about the underlying mechanisms. Hence, this study develops a theoretical framework that disentangles effects of composition (selection into lone motherhood) and lone motherhood per se (shaped by institutional contexts) on lone mothers’ poverty. Three major routes to lone motherhood can be identified that differ regarding their timing, selectivity and related risk of poverty: lone motherhood after marriage, after cohabitation, and out-of-relationship child birth. Using data from the German Socio-Economic Panel, this study first analyses the relationship between the three routes and poverty before and during lone motherhood. Second, conditional difference-in-differences models are used to identify the lone motherhood effect on lone mothers’ poverty controlling for composition. Results reveal that two years prior to the transition, all, but particularly cohabiting to-be lone mothers, already show notably higher poverty rates than women who do not experience lone motherhood. Moreover, divorced lone mothers face the highest poverty-enhancing effect of lone motherhood on poverty.

在德国，孤单的母亲是受收入贫困影响最大的群体之一。先前的研究表明，单身母亲的社会构成（例如，就业状况，年龄，子女数量）和体制背景（例如，家庭和劳动力市场政策）对于解释这种高度脆弱性都是至关重要的。然而，我们对潜在的机制知之甚少。因此，本研究建立了一个理论框架，该框架阐明了构成（选择单身母亲）和单身母亲本身（由制度背景决定）对单身母亲贫困的影响。可以确定三种实现单身母亲的主要途径，它们在时间安排，选择性和相关的贫困风险方面有所不同：婚后，同居后的独生子女以及非关系生育子女。使用德国社会经济专家小组的数据，这项研究首先分析了孤独育儿之前和期间这三种途径与贫困之间的关系。其次，使用条件差异模型来识别独生子女对单身母亲控制贫困的影响。结果显示，在过渡之前的两年，所有妇女，特别是同居的即将成为单身母亲的人，已经显示出比没有单身母亲的妇女明显更高的贫困率。此外，离婚的单身母亲面临着单身母亲对贫困的最大的增贫作用。结果显示，在过渡之前的两年，所有妇女，特别是同居的即将成为单身母亲的人，已经显示出比没有单身母亲的妇女明显更高的贫困率。此外，离婚的单身母亲面临着单身母亲对贫困的最大的增贫作用。结果显示，在过渡之前的两年，所有妇女，特别是同居的即将成为单身母亲的人，已经显示出比没有单身母亲的妇女明显更高的贫困率。此外，离婚的单身母亲面临着单身母亲对贫困的最大的增贫作用。