A random birthplace is a different kind of lottery

First, how many new stories begin?

The UN's World Fertility 2024 report gives about 132 million births worldwide for 2024. It places the earlier annual peak at about 146 million in 2012. The 2024 figure is a modelled projection; the 2012 figure is a historical estimate. Source: UN DESA, World Fertility 2024, page 4. The underlying series labels 2024 onward as projections. UN dataset methodology.

For a sense of scale, divide 132 million by the 366 days of 2024, then by 86,400 seconds per day. The result is about 4.2 births per second. That is our calculation from the report's rounded annual figure; it describes an average across the year, not a steady rhythm in every second.

Two questions, two different denominators

For a randomly selected resident, a place's probability is its population divided by the total population of all the places included. For a randomly selected birth during a particular year, use its births divided by total births in the same set of places and year.

The World Bank defines the crude birth rate as annual live births per 1,000 people, using a midyear population estimate. So an approximate annual birth count can be calculated as population multiplied by that rate, divided by 1,000. Use matching years and consistent coverage when comparing places. Source: World Bank indicator definition.

Imagine two pixel villages

Here is a completely fictional example. Sun Village and Moon Village each have 1,000 residents. During our imaginary year, Sun Village welcomes 30 babies and Moon Village welcomes 10.

• Choose from all 2,000 residents: each village has a 50% share.
• Choose from the year's 40 births: Sun Village has a 75% share, while Moon Village has 25%.

The arithmetic is simple: 30 divided by 40 is 0.75. Nothing about the villages' population sizes changed. We changed the group being sampled. Equal-sized crowds do not automatically contribute equal numbers of newborns.

Try drawing both versions with twenty dots. The resident picture gets ten dots per village. The birth picture gets fifteen for Sun Village and five for Moon Village. The same pair of places now tells two different, equally valid stories.

What this means for a random life

When a life game starts with a newborn, birth-weighted sampling is one possible way to frame the starting-place question. The examples in this article explain the mathematics independently of the app's in-game outcomes.

It is also a useful habit outside games. Before sharing an eye-catching percentage, ask what sits underneath it: all residents, all births, or a particular age group? Then check the year. Once the denominator is clear, the fun fact becomes easier to understand—and much harder to accidentally misread.