Hey Larks, thanks for the great comment. I think it gets at some key assumptions one has to consider when evaluating this as an intervention. We didn’t end up going into that in this post, but happy to cover it below.

I both see the scenario in which the benefits outweigh the costs (the one in which we are happy to incubate this charity), and I also see scenarios where the costs are higher than the benefits (in that case we wouldn't recommend it). Specifically: 

Existing people get the benefit of building relationships with these new people.

When you consider the context of the families that an intervention such as this would be impacting I think the benefits you layed out are a lot smaller (to the point they do not largely change the calculation). They are typically families with large family size (my expectation is that the 4th child or grandchild does not carry the same weight as the first, particularly when it comes to long term support of the family). 
 

Division of Labour - whereby people specialise in one specific area they become more efficient at it. The larger the population, the more specialisation it can support.

They are also typically in low-income jobs with limited specialization (often family planning is most needed in families earning income from primary agriculture). I expect that averting unwanted pregnancy frees up the income of the household to spend on the current family, e.g. on more education opportunities or a more nutritious diet that has further positive flow-through effects on the family. I think this same education confounder also cross-applies to creating more artists and scientists. It's not at all clear to me that net higher population vs higher average education but smaller families would result in this.   

Many things have increasing returns to scale, and so are more efficient with larger populations 

Although I have some sympathy for the economies of scale arguments, I think depending on the country the efficiency effects of having a very young or rapidly growing population trade off against this in quite an unfavourable way. I also think there are less economies of scale in less connected and more rural settings. (E.g. things like electricity or water have limited scale in these locations.) I also expect these benefits to be quite small relative to the current factors we consider.  
 

It is of course possible that these benefits might be outweighed by the costs outlined in the report. But we cannot simply assume  that this is the case. 

When we are modelling cost-effectiveness on that sheet we are not aiming to take into account all of the externalities, but rather compare between interventions within family-planning, so you probably won’t find them there. We would use a different methodology to take them into account. But I take your point about the broader cost-benefit considerations. 

 As life is good for most people, this is a major advantage. They get to experience the joys of playing and growing and love and all the other good things in the world.

I do think you have hit on the really key assumption that can change one’s model of family planning though. “Life is good for most people”. We spend a considerable amount of time and work thinking about it and I agree that there is a lot of moral and epistemic uncertainty around the issue. It is probably the hardest thing to take into account when it comes to the assessment of moral weights of various outcomes. Depending on how one takes it, it can either result in 60 years equivalent of utility or disutility. However, I think again we have to look at the population very closely. Populations that do not have access to family planning information or counselling are more likely to have lower happiness levels. The country our last family planning charity chose to work in is Nigeria, where the average happiness goes up and down between 5 and 6 out of 10. Another country we recommend is Senegal, where the numbers are even lower. But I would say even this data is not precise enough as even within countries populations without access to family planning are typically far lower income than average. Also, the child whose existence would be prevented would be a child the family would prefer not to have, and this seems likely to have an effect on the average happiness of both the child and the family. We know the SD of happiness in Nigeria is pretty large ~2.5 (this variation is also typical across other locations). It's hard to know exactly what happiness that person would have over their life. It could easily be in the 3-4/10 range. If you think a year lived at 3-4 is net positive and something you would want to create more of, then indeed this is a huge factor against family planning. If you think its net negative then its a huge factor in favour. I think this is one of the key ethical questions. It comes down a lot more to do with positive vs negative leaning utilitarianism and how you view various weightings of subjective well being. This is a factor we considered a lot when thinking about it and although I think there are defendable different perspectives our team generally came down on the side of this effect being a net positive for family planning (some more info here). 

I do think we could have made improvements to the report to make some of these judgement calls more clear and bring people's attention to the factors that affect the analysis significantly. We do tend to discuss these considerations and outline when the results of the general judgement about family planning may differ according to some ethical or empirical differences in much greater depth with incubatees who are considering working in these areas and it’s indeed a complex issue, because of this we have typically found it it easier to discuss it in conversation rather than in writing. I agree that the report could have been better written to take that into account. 

Larks, as much as you consider the provided cost-benefit analysis to be "naive", I am afraid the same applies to several of the counter-points you mentioned. Could you please give some sources that support (a) your claims and (b) are broadly generalizable or generalizable to a degree they should support policy? Specifically, I think some of your assumptions you just take as given even though there is a lot of high-quality evidence to the contrary. I was also a bit disappointed that you did not want to answer on the below issues when you made that identical post the first time around. It seems to me like it is informed by an inherent pro-natalist view without the proper analysis of underlying issues and well-established complexities to the contrary. For the four bullet points in your post, I would like to provide counter-arguments (which I would be happy to discuss if you're interested) why they might not be correct and would greatly appreciate if you could provide generalizable evidence supporting your bullet points:

"benefit of building relationships with these new people":

What is the EV here? Does this scale linearly with the amount of people that come into existence? Do you have any sources for the amount of "additional happiness" vs "additional suffering" caused by these humans to other life-forms (cf. average global meat and fish consumption)? There are various studies that basically say that the relation between "children" and "happiness" is complicated at the very least, for example seen in the following articles. All in all, happiness for parents mostly decreases while they actively rear children, for example:

• Are People Who Have Kinds Happier? Not really.
• Dan Gilbert has some good statistics on marital satisfaction in "Stumbling upon Happiness", posted e.g. here: https://twitter.com/kiminsalaco/status/883493590638448640

Many things have increasing returns to scale, and so are more efficient with larger populations - e.g. mass transit, factory size, power plant size.

This depends on the kind of growth and whether the government and economy of a country with a growing population can adequately supply all these points you mentioned. Many countries only experience a real bump in development due to the Demographic Dividend, i.e. when birth rates fall (s. for example Johns Hopkins University and Wikipedia). In many countries, unsustainable population growth depletes financial resources of governments and prevents long-term strategic investments by tying budgets to short-term social support. The same applies to families: Family income only increases with more family members once these new family members reach working age. Before that, they do not have more, but less money to spend on the individual, including education and training. In other words: Growth in population is not good for a country per se. It needs to be sustainable and supportable (by government and family budgets) for a country and its population to profit. Many countries such as Rwanda only really developed once they managed to profit from the Demographic Dividend, as established in countless peer-reviewed articles.
 

Division of Labour - whereby people specialise in one specific area they become more efficient at it. The larger the population, the more specialisation it can support.

This only holds true if the society that grows can provide adequate education opportunities to support the specialization you mentioned. Good counter-examples to your argument are, in fact, the fastest-growing populations we know: Sub-Saharan countries. If your argument was generally true, countries such as South Sudan, Angola, Malawi, Burundi, Uganda, Niger, Burkina Faso and Mali should experience greater degrees of professional specialization. Do you have any evidence to support this? I would be very happy to see it!

The new people can become inventors and scientists or artists. Because ideas can be copied with ~ zero cost, these people can provide a benefit to everyone, so the higher the population the better.

Do you have any studies here that show the likelihood of people in the fastest-growing societies by birth numbers becoming inventors or scientists?

The scientific publication that has received the most supportive signatures from scientists ever, the World Scientists' Warning To Humanity, specifically urges world leaders to reduce human population growth. Quoting from Wikipedia which provides the primary source:

The Second Notice has more scientist cosigners and formal supporters than any other journal article ever published.

The Second Notice specifically states:

By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperilled biosphere.

Do you think that this notice is generally biased or naive?

Hi Rafael,

Thanks for your thoughtful response – it’s great to hear your impressions on our research!

"Do you know of other organizations that follow this approach, given your point that this is one of the few times a woman will come in contact with the health system?"

The expert view section of our report (p. 16) has the most information about other actors in the space. Key points:

• Several groups (e.g. FP2020, FHI360, USAID, IntraHealth) are working on PPFP due to the strong evidence of its effectiveness, but only a few specialize in it – most work on PPFP alongside other family planning interventions. 
• Jhpiego came up in conversation with experts as a key actor working on PPFP. 
• Overall it seems that, while some work is taking place to promote PPFP, there’s still a lot that remains to be done – particularly in neglected geographies.
   

"Your estimate for the cost of one tonne of CO2 averted (3 tonnes per USD spent or 0.33 USD per tonne of CO2 averted) would place your intervention among some of the most cost-effective for climate change. Is this generalizable to family planning in general and, if so, how?… That leads me to think that family planning and fulfilling unmet contraceptive needs would generally be a very effective intervention to support for multiple outcomes. What is your view on that? Is this generalizable to other countries or not?"

In the specific case of family planning, CE is uncertain but optimistic that family planning and fulfilling unmet contraceptive needs can be impactful on a range of outcomes. However, we don’t think that CEAs should be taken at face value and are very uncertain of the true effect on climate change. More in-depth work is needed to estimate the effect.  You can read more about our thoughts in our blog post on why we chose to research family planning. Project Drawdown also has a nice summary. The organization Having Kids is also doing some work that might interest you. 

Founders Pledge has previously analyzed the effect of lifestyle changes that could affect the climate and looked into “having one fewer child”. The results change dramatically depending on whether or not you account for policy changes leading to reductions in future generations’ emissions. 

All that to say, we would be cautious about generalizing more broadly, and would not expect the same numbers to apply. This is also why for example we discount studies that take place in different contexts when examining the evidence for a particular intervention: generalizations get messy.

As a quick example for how generalizations about family planning and climate change can get tricky: per capita emissions are much higher in first world countries than in developing contexts, but fertility rates (i.e. the average number of children born to each woman) are much lower. If we want to compare the two, we need to account for these and many other such differences. CE hasn’t looked into this question in depth, although our implementation report (which we share with co-founders) lists a couple more countries in addition to Ghana and Nigeria as potentially promising. 

We hope that helps answer your questions! Thanks again for engaging with our research. :)