Population Size/​Growth & Reproductive Choice: Highly effective, synergetic & neglected

In this post I want to make several points regarding a cause area that is neglected both by the mainstream and by EA. It is neglected by EA even though this cause even though it is:

  • highly effective

  • cheap to effect change

  • synergistic with several other EA focus cause areas, including climate change, bio risks, poverty and animal suffering

  • neglected by the mainstream

  • big funding gap

The cause area I am talking about is population growth (also known, depending on your perspective, as reproductive choice, family planning, or population size reduction). Without further ado...

Synergistic & Network Effects

Both high population size (status quo) and population growth (positive delta) negatively effect several cause areas commonly viewed as aligned with EA reasoning:

  • Climate change

  • Poverty, education and economic development

  • Bio risks

  • Individual suffering

In this section, I want to quickly go into how population growth slowdown or population size reduction could have severe positive effects on the aforementioned cause areas.

Climate change /​ Global warming

Climate change /​ global warming is, as we all know, primarily driven by human activity and consumption. It is a function of (number of consumers) * (consumption level). Both variables are currently quickly rising. In fact, population growth has cancelled out 75% of all improvements in energy and emission efficiency achieved in the last three decades [1]. Project Drawdown has identified population growth reduction or population reduction—anything that brings down human population numbers—as the second-most effective means of reducing global warming. However, likely for political reason, this action point is hidden within Project Drawdown’s greater policy recommendations for “Girls’ education” and “Family planning” [2]. When resolving the arbitrary split between these two categories, family planning/​access to contraceptives and girls’ education/​women empowerment becomes the second-most effective policy action [3]:

On an individual level, having one child less is the most effective action an individual can take, as emissions scale with the number of individuals on the planet [3]:

This is immediately obvious, as no action increases your carbon emissions more than adding one more individual which will emit basically as much as you.

For more information, have a look at [3].

Poverty, Stunted Economic Development & Education

One lesser known fact about population growth is that the causal relationship is very likely—at least in our current times—not one way or potentially even reversed. Previously, it was believed that people have more children when they are poorer; however, at the moment, it seems that more children contribute more strongly to poverty and cultural reasons play a bigger role in the number of children in at least some countries [15]. Some studies have found that in some cultures a better economic situation does not lead to less, but to more children because they are a status symbol; in almost all countries, on average, though, desired fertility is lower than actual fertility [16]. That means that, even in countries where people want to have a high number of children, they still have an unmet need for contraception.

In several countries, population growth leads to more poverty rather than less. The reasons are the following:

  • Most countries with high population growth have economies mostly based on unskilled and/​or manual labor with too few education opportunities. This increases competition for unskilled employment opportunities and depresses wages.

  • Governments cannot afford to build infrastructure that keeps up with exponential population growth, as their revenue and budgets do not grow accordingly (but, rather, stay quite the same). Poverty depletes government budgets through growing social spending, with is lacking in infrastructure or education. This effect creates a vicious cycle: Population growth increases pressure on government budgets, which leads to less education, which exarcabates poverty and population growth. In general, population growth “eats” all economic development.

  • Poverty also strikes at the family and individual level, as effective wages decrease, competition for employment increases, education opportunities are scarce. This arguably leads to suffering and a reduction in personal satisfaction.

  • The number of dependents increases, increasing financial strain on families.

  • Demographic risks: At one point, there will be a reversal in the demographic pyramid. The earlier that reversal is achieved, the less dire the consequences when it happens.

  • Political risks: Some researchers argue that the big migratory movement from Africa and the Middle East to Europe is a consequence of limited opportunities for too many people in source countries.

For some sources on how population growth exarcerbates poverty and destroys government budgets, thus stunting economic development and education, see e.g. [4], [5] and [11].

Bio risks & zoonoses

Population growth and consumption directly lead to habitat loss. Several studies show that encroachment is a main driver in zoonoses like CoViD-19. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) has recently released a report that clearly states that population growth, animal habitat destruction, wet markets and encroachment are increasing the risks for pandemic zoonoses drastically [6].

Individual suffering & Extent of the problem

This is the one point I couldn’t find proper studies for. I argue, however, that women—who are 50% of the global population—suffer greatly when they are forced to bear children against their will. The extent of this is huge. Stealing from Wikipedia, but well cited [7, 8]:

The global rate of unintended pregnancy was estimated at 44% of all pregnancies between 2010 and 2014, corresponding to approximately 62 unintended pregnancies per 1000 women between the ages of 15–44 years old. While unintended pregnancy rates have been slowly downtrending in most areas of the world, different geographic regions have different estimated unintended pregnancy rates. Rates tend to be higher in low-income regions in Latin America and Africa, estimated at 96 and 89 unintended pregnancies per 1000 women, respectively, and lower in higher income regions such as North American and Europe, estimated at 47 and 41 unintended pregnancies per 1000 women, respectively.”

Additionally, cultural norms prevent (protected) sex for pre-marriage in many high-fertility countries [9]:

“Young, sexually active, never-married women face much greater difficulties in obtaining contraceptives than do married women, in large part because of the stigma attached to sexual activity before marriage. Some 44% of never-married women in need of contraception (most of whom are young) are not using modern methods, compared with 24% of married women in need.”

At present, it is estimated that there are at least 240 million women that want to have access to contraceptives but don’t. The number of women who given a choice would also desire access to contraceptives, would likely be much larger.

Animal suffering

The amount of animal product consumers directly influences the number of animals in farming, most of which is factory farming nowadays. The number of consumers who consume animal products has exploded in the last few decades [17], due to dietary patterns changing away from mostly plant-based diets to diets including more animal products [18].

In other words: The population size pretty much directly determines the amount of animal suffering in farming.

UN Sustainable Development Goals

Almost all UN SDGs are directly affected by human population size [12]. For the sake of brevity I won’t go into details here because for most SDGs this connection is pretty obvious. If you want, though, I can go into details in a response.

Costs to Effect Change & Effectiveness

Preventing unintended pregnancy for a full year is cheap, at about 10 USD per woman [9]. Assuming that a woman wants to stop having kids, and assuming that she has 25 more productive years, and lastly assuming 2.5 ton of CO2 p.a. per person (this is the number for egypt—I would expect per-capita CO2 emissions to rise in the future), 250 USD to eliminate a lifetime of CO2 (180 tonnes at current levels in Egypt). That, it turn, means about 1.38 USD per permanently eliminated/​prevent ton of CO2, which is extremely cheap. It is almost as cheap as Cool Earth’s (very optimistic!) estimates and much cheaper than any technological solutions known to us. Likely, it is even cheaper than 1.38 USD because of the effect of preventing the consumption and emissions of any offspring (and offspring’s offspring, and so forth) of the child that will thus never come into existence. Assuming, furthermore, that the same 10 USD p.a. per user do not only prevent one but two children, cost-effectiveness increases even further. Assuming two children permanently not being born and that offspring’s offspring is also prevented, this intervention would easily be the most effective for climate change known to EA; though harder to prove, I think this might even hold if only one additional child is prevented per woman.

In general, 10 USD per user per year can greatly improve the lives of those who don’t want more children, can set overburdened economies back on track and decrease strain on struggling families. And you get all these network effects from focusing on just a few interventions that target the upstream problem of women’s rights/​opportunities/​education and reproductive rights.

I would like to paint the following picture in your mind: A dependency graph. If you draw a dependency graph for many cause areas, women’s rights/​education/​empowerment and reproductive rights/​familiy planning are at the top and influence many, many other cause areas. Thus, by targeting an upstream cause area, we will have positive effects on many downstream cause areas. This makes it an efficient and effective intervention.

As you can see above, preventing CO2 emissions is already pretty cheap by following a family planning/​planned parenthood approach. If we manage to do a calculation of all positive effects, I am pretty sure family planning/​planned parenthood/​women’s education & rights would come out as one of the most cost-effective “interdisciplinay effects” interventions possible.

Cause Area Neglectedness & Funding Gap

I guess I don’t need to explain this one. The topic is completely neglected in the mainstream. What is sad, in my opinion though, is that it is completely neglected by EA as well. It literally ticks all the EA boxes: Being neglected by the mainstream, being highly effective (as a cause area of its own and due to positive cross-effects on EA focus areas) and being cheap to have signficant effects on several cause areas at once.

The UN Population Fund alone currently has a funding gap of about 250 Million USD. Reliable total funding gap numbers are hard to come by, the most reliable numbers I have found are between 1 billion USD p.a. and 8 billion USD p.a.; many sources such as this one [13] place the funding gap at around 3.6 billion USD annually.


I will just name a few charities in this area I know and donate to—in no particular order:

  • Population Matters

  • Population Services International

  • Population Media Center

  • Marie Stopes

  • Deutsche Stiftung Weltbevölkerung

Wrapping it up

This post is only a very superficial overview of why EA should place much greater focus on anything that reduces population growth and/​or size (in an ethical way, of course). Ethical and consent-based ways to reduce population growth and/​or size are cheap, cost-efficient, have signficant positive effects on several other EA focus areas, and are neglected by the mainstream. I personally am very convinced that this cause area and different interventions in it are highly aligned with EA views. With this post I want to raise a bigger discussion and awareness of this cause area in the broader community and give it the recognition it should receive from EAs. I would like to see this cause area researched better by GiveWell and other EA-aligned groups, especially those doing cause prioritization.


[1]: Aalok Ranjan Chaurasia: “Population effects of increase in world energy use and CO2 emissions: 1990-2019”
[2]: Jane O’Sullivan for Overpopulation Project: “Drawdown: a review of the Review”
[3]: Population Matters on Climate Change
[4]: Steven W. Sinding: “Population, poverty and economic development”
[5]: Klasen, Stephan; Lawson, David (2007) : The impact of population growthon economic growth and poverty reduction in Uganda
[6]: IPBES Workshop Report on Biodiversity and Pandemics
[7]: Wikipedia: Unintended Pregnancy
[8]: Bearak, Popinchalk, Alkema, Sedgh: “Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model”
[9]: Guttmacher Institute/​UNFPA: “Costs and Benefits of Investing in Contraceptive Services in the Developing World”
[10]: Kenneth Gillingham: “Carbon Calculus”
[11]: Mona Khalifa, Julie DaVanzo, David M. Adamson: “Population Growth in Egypt—A Continuing Policy Challenge”, RAND Corporation
[12]: UN Sustainable Devlopment Goals (SDGs)
[13]: “What Would It Cost to Meet Family Planning Needs in Developing Countries?”
[14]: John Bongaarts and John Casterline: “Fertility Transition: Is sub-Saharan Africa Different?”
[15]: Muhoza, Broekhuis, Hooimeijer: “Variations in Desired Family Size and Excess Fertility in East Africa”
[16]: Anne Bakilana and Rifat Hasan: “The complex factors involved in family fertility decisions”, World Bank Blogs
[17]: Our World in Data: Meat and dairy production
[18]: UN Food and Agriculture Organization (UNFAO): “Global and regional food consumption patterns and trends”