# I. INTRODUCTION

Polygamy<sup>1</sup> is widespread in many developing countries, and although it has been declining since the 1970s, it remains persistent especially in sub-Saharan Africa. In 2000, the overall prevalence of polygamy was 28 percent in the 34 countries studied by Fenske (2015), based on data from the demographic and health surveys on evermarried women of childbearing age. Although in a polygamous society only a certain proportion of unions actually become polygamous, almost all monogamous women are faced with the risk of polygamy. As noted by Antoine (2002), in Senegal a majority of women will be in a polygamous union at some point in their lives.

Socio-anthropological research suggests that the arrival of a second wife is mostly viewed by women in a monogamous union as a threat (Madhavan 2002; Antoine 2002). This threat may be exploited by the husband to monitor his wife, who has in general no say in this decision (Madhavan and Bledsoe 2001). The extensive literature review provided by Bove and Valeggia (2009) substantiates this fear since it shows a negative correlation between polygamy and women’s health. However, the economic literature is silent on the potential impact of the anticipation of polygamy on the allocation of resources within households. In particular, no paper, to our knowledge, has investigated the strategies that women in monogamous unions may implement in order to avoid the arrival of a cowife or to protect themselves against such an event. Only rare qualitative evidence of such strategic behaviors is provided by demographers: Antoine (2002) mentions one of these strategies of monogamous wives consisting of not sharing their income with their husband and driving him to spend more in order to decrease his saving capacity and impede the arrival of a cowife. Marrying a second wife is indeed costly to the husband: savings are needed to pay for both the wedding and the bride price, which has remained high and remarkably stable over time in Senegal, according to our survey data. As for women, they may have incentives to increase their own savings so as to protect themselves against the arrival of a cowife, which may be viewed as a negative income shock. Depending on their capacity to protect their savings from their husbands, we expect different strategies of monogamous wives in response to an increased risk of polygamy. This article thus intends to fill a gap in the literature on polygamy by exploring the impact of the threat of polygamy on monogamous spouses’ saving behavior and resource allocation decisions.

The case of Senegal is particularly interesting since previous studies have shown that the prevalence of polygamy is still high and declines at a slower pace than in most other sub-Saharan countries. The share of young women (aged 20 to 24) in a polygamous union has even increased in rural areas from 1986 to 1997 Antoine (2002). In 2006, according to our data, 38 percent of Senegalese married women aged 15 to 60 are in a polygamous union.

We use original individual panel data from a nationally representative survey ( _Enquête Pauvreté et Structure Familiale_ [PSF]) conducted in 2006–7 and 2010–12. Our data are unique and particularly suitable for this analysis. Indeed, while survey data in the developing world generally collect information on savings at the 1 In this article, we use the generic term polygamy for polygyny: polyandry does not exist in Senegal.

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