 Global anti-natalism opposes procreation in general. One global anti-natalist position holds that in all cases procreation is a harm to those brought into being. Benatar argues that while existence brings pains as well as pleasures, non-existence is a lack of pains and pleasures. While pain is bad, absence of pain and pleasure is not bad, so it is always worse to be than not to be (Benatar 1997, 2006; see also discussion of Shiffrin 1999, below; for responses, see Overall 2012, Benatar and Wasserman 2015). Other global anti-natalist positions focus on harms or costs to others. An environmentalist anti-natalism argues that procreation is wrong for the same reasons overconsumption is (Young 2001, MacIver 2015). An opportunity-cost anti-natalism argues that the money spent on rearing a child would be better spent on ameliorating the lives of those already existing (Rachels 2014). And a misanthropic anti-natalism argues that humans cause so much harm – to other humans, non-human animals, and the environment – that there is a duty not to procreate (Benatar 2015). Others have argued that the availability of children needing homes creates strong moral reasons to adopt rather than to procreate (Friedrich 2013, Rulli 2014). There are also intermediate positions. For example, Sarah Conly argues that the interests that ground a right to procreate can be satisfied with only one child and so it may be permissible to restrict the number of children an individual creates when costs to third parties from overpopulation are substantial (Conly 2005, 2016; see also Statman 2005).