Jan Erik Buaroey - Assignment #3: Birth rate and ideology

Introduction
Artificial birth control is prohibited among practitioners of Catholicism. Based on that, it would be reasonable to assume that nations with large Catholic populations would have higher birth rates than nations where artificial birth control is not prohibited for a significant population. To examine the validity of this assumption, I have gathered data from six nations where at least 80 % of the population is Catholic, and data from three nations where less than 4 % of the population is Catholic.

The Catholic nations I chose for this assignment are Cuba, Ireland, Mexico, Poland, Portugal and Spain. I chose those nations because they all have above 80 % Catholic population, and because I expected to find differences between them when examining them closer.

The non-Catholic nations I chose are Armenia, Norway and Thailand. I chose those nations because they all have less than 4 % Catholic population, and because I expected to find differences between them as well.

The ten variables I chose to look at are presented in the table below. In addition to the obvious variables Catholic population and birth rate, I also wanted to look at other variables to see if there could be anything that correlates with birth rates. The first one is contraceptive prevalence rates. This variable gives the percent of women of reproductive age (15-49) who are married or in union and are using, or whose sexual partner is using, a method of contraception according to the date of the most recent available data (CIA World Factbook).

I also looked at infant mortality rates, life expectancies at birth, how big part of the population that lives below the poverty line, school life expectancies (the total number of years of schooling primary to tertiary that a child can expect to receive (CIA World Factbook)), literacy, how many in the population that lives in urban areas, and GDP per capita.

	Cuba	Ireland	Mexico	Poland	Portugal	Spain	Armenia	Norway	Thailand
Catholic population	85 %	87.4 %	82.7 %	89.8 %	84.5 %	94 %	< 4 %	1 %	< 0.7 %
Birth rate/1000	9.92	15.50	18.61	9.88	9.59	10.14	12.86	10.80	12.66
Contraceptive prevalence rate	74.3 %	64.8 %	70.9 %	72.7 %	86.8 %	65.7 %	54.9 %	88.4 %	79.6 %
Infant mortality rate/1000	4.76	3.78	16.26	6.30	4.54	3.35	17.59	3.47	15.41
Life expectancy at birth	78.05	80.44	76.86	76.45	78.85	81.37	73.75	80.44	74.05
Below poverty line	NA	5.5 %	51.3 %	10.6 %	18.0 %	21.1 %	35.8 %	NA	7.8 %
School life expectancy (primary to tertiary education)	15	19	14	15	16	17	12	18	12
Literacy	99.8 %	99.0 %	93.5 %	99.7 %	95.4 %	97.7 %	99.6 %	100.0 %	93.5 %
Urban population	75.0 %	62.0 %	78.0 %	60.9 %	61.0 %	77.0 %	64.1 %	79.0 %	34.1 %
GDP per capita ($)	10,200	42,600	15,600	20,900	23,800	31,100	5,900	55,900	10,300

 Source: CIA World Factbook (https://www.cia.gov/library/publications/the-world-factbook/)

Analysis
We can see from the data in the table that a high percentage of Catholicism does not correlate with a high birth rate. Even though both Ireland and Mexico have higher birth rates than the non-Catholic nations, the other four Catholic nations all have lower birth rates. What is interesting though, is that people in the Catholic nations uses relatively more contraceptives than one might have assumed given the high percentage of Catholicism. Even more interesting is it to find that there does not seem to be a statistically significant correlation between being a Catholic or not and the use of contraceptives. Likewise, there is no statistically significant correlation between birth rates and the use of contraceptives either.

The infant mortality rates vary among the nine nations examined. Mexico has the highest birth rate and the second highest infant mortality rate, but Ireland, which has the second highest birth rate, has a relatively low infant mortality rate. Armenia and Thailand, which have the highest and third highest mortality rates, also have a somewhat higher birth rate than most of the other nations (except Ireland). There is a weak correlation here, but it is not enough correlation to be statistically significant. Even weaker is the correlation between birth rates and the life expectancy at birth.

Sadly I am missing data for two nations regarding the percentage of the population living under the poverty line. Even though it is not statistically significant, it might be possible to see a weak correlation between living under the poverty line and the birth rates. The school life expectancies do not correlate significantly with the birth rates, and neither do literacy. How urban the population is does not correlate with the birth rates at all, likewise with GDP per capita.

Conclusion
I could not find any statistically significant correlation between birth rates and any other of the variables. There can be many explanations for that, and the results would most likely come out differently if I choose other nations and do it all over again.

Two of the variables do actually correlate weakly with the birth rates. Those variables are the infant mortality rates and the percentage of the population that lives under the poverty line. These variables both have a Pearson product-moment correlation coefficient (PPMCC) around 0.56-0.57. This does not make them statistically significant, but we can see a trend. A broader selection of nations would possibly have given us a higher PPMCC, and thus making it more significant.

But what does it mean that there is a correlation, even if it is weak, between these two variables and the birth rates. Why are poorer people with a higher infant mortality rate having more children? The answer lies in animal (and human) nature. When someone lives in a stable environment with enough sources of food and security they tend to get less offspring. This is because there is a better chance for the offspring to grow up. Vice versa, when someone lives in an unstable and unsecure environment they tend to get more offspring because chances are that not everyone will grow up and continue the family line. We find this also in the animal world.

There are of course many factors that affect how many children a family has, but a lot can be explained by nature. There is no coincidence that underdeveloped nations have higher birth rates in general, and it certainly does not have anything to do with religion. The Catholic prohibition does not seem to exist in behavior, and not all practice what they preach. But let us have in mind that even if a nation has a high percentage of Catholics it does not mean that all are practicing Catholics, and some probably practice Catholicism more serious than others.