Costa Rica is a very small country. To give you an idea it is only the size of West Virginia and just under 20,000 sq miles. The terrain of Costa Rica is very rough with two coasts that are on average 60 miles apart and mountain ranges that climb as high as 13,000ft. All of this has played a roll on the demographics of Costa Rica over the last thousands of years making areas hard to be reach and much of the country very isolated from other parts. More recently what has kept the Costa Rica population just over 4.5 million is it's attention to education and development. With many of the countries in the world having exponential population growths mostly all including the developing countries in the America's and the poorer countries of Africa Costa Rica has held its population steady lingering just around 4.5 million. The population of Costa Rica is 99% renewable clean energy which means that the per capita footprint of your average Costa Rica is well below the world average.
With the 4.5 million the last census was in 2010 and it was no surprise that the population maintained where it was. Credit is due to education and also the development of city life. Many families who were farmers now have children looking for the urban life-styles going to University, working in call centers, and living a more modern way of like. All of this contributes to the mentality of not needing to have 8 kids to work the farm, security for your old age, or the traditional non-contraceptive life-style.