a 10-year old girl's hypothesis (the 10 cent theory)

1. The hypothesis

This hypothesis, although it may seem surprising, was thought up by a 10-year old girl called Preetha, while we were talking about poverty during a train journey in Southern India, from Bangalore to Anantapur in January 2006. This is her hypothesis:

“I am sure that if all the adults from rich countries saved a dime every day for a year, they would have enough money to ensure schooling for every child in poor countries”.

Of course, when I heard this I was perplexed, both by the form of the message and its content (I repeat that this girl was just ten years old! And only spoke a little English). In fact, her reflection captured my attention to the extent that I noted it down in a little pad I was carrying. However, I never imagined that her hypothesis could be true. Of course the girl had no idea how many adults there are in developed countries, and I don't think she knew how to multiply, nor did she know the cost of educating a child in a developing country. In fact she was one of the millions of girls and boys who don't go to school; she had stopped going a few months back to look after her home and take care of her younger siblings while her parents worked - a very normal situation in rural India, especially for girls. But going back to her hypothesis, it seemed absurd that with such a small effort enough money could be collected for an enterprise on this scale. I can't remember what my answer to her was; I am sure I must have smiled and told her that things weren't that simple.

However, during the following months on my return from India, I often thought about Preetha and our conversation on the train. Finally, a few days ago I checked the data simply out of curiosity, and with a totally unexpected result: the hypothesis was on the nail (at least with respect to the data and quantity - whether it would be viable in the world we live in is another thing). Here you can see the proof.

2. Demonstration

The proof is really very simple. First we need to know how many adults there are in rich countries. Since "rich countries" is a very relative term, I have chosen the 25 most developed countries according to the ranking in the 2006 Human Development Report of the United Nations.

These countries are: Norway, Iceland, Australia, Ireland, Sweden, Canada, Japan, United States of America, Switzerland, Holland, Finland, Luxembourg, Belgium, Austria, Denmark, France, Italy, United Kingdom, Spain, New Zealand, Germany, Hong Kong, Israel, Greece and Singapore.

Once the countries have been chosen we can calculate the total population by adding the partial populations. Using the statistical data of the United Nations (unstats.un.org), we can see that the total population of these 25 countries is: 882,300,000.

From this total number of inhabitants we have to select the adults. Using the same statistical data, we can find the population aged 15 and over for each country, so the total adult population for the 25 selected countries is: 725,828,100.

Of these adults we need to subtract those who are poor. We have to remember that there is also poverty in developed countries (the so-called Fourth World). Using the same data as the United Nations, it has been calculated that the average percentage of poor people in these 25 countries is 10.58% (in this case poor is taken to be those with a per capita income under half the average).

Subtracting this percentage from the total number of adults we get a final result of 649,035,487 adults who are not poor.

Now all we have to do is multiply this population by 365 days and by 10 cents per day (we will use the dollar as the most international currency reference). The final result is that 23,689,795,276 dollars would be collected, in other words approximately 23,689 million dollars.

It is currently thought that there are more than 130 million children of primary school age who are unable to go to school. Bearing in mind that according to the World State of Infancy report of 2005, achieving universal primary education by 2015 would cost around 9100 million dollars per year, we can conclude that Preetha was not at all far off the mark and that the 10 Cent Theory is really true (at least from a statistical point of view. Of course its viability in today's world is a different thing).