figuring out mortality rate

Question

if a country lowers its mortality rate while its birth rate remain the same,

 

a. the size of the population of that country will decrease

 

b.  the size of the population of the country will increase

 

c.  the country will achieve a zero growth rate

 

d.  the country will avoid a population explosion

Answer 1

This question is actually not well-worded. Here's a hypothetical example to prove my point.

 

Suppose the following apply for a specific country at one point.

1. 25 people are born per day
2. 40 people die per day

 

The country's population will decrease because there are 15 more deaths per day than births per day. That is, the population growth rate is -15 persons per day.

 

Now let's say the following is true at another point.

1. 25 people are born per day
2. 35 people die per day

 

The mortality rate has decreased and the birthrate remains the same. But the country's population is still decreasing. The population growth rate is -10 persons per day. Though the population is not decreasing as quickly as before, it is decreasing nonetheless. So there is no way to determine the answer with the givens alone.

 

The question is poorly written. But B is the most logical choice nonetheless; the population will be increasing faster than it was before or decreasing slower than it was before.

Answer 2

Mortality rate is the rate at which people die for any reason, while birth rate is just how frequently new people are born.

• High Mortality Rate + Low Birth Rate = decreasing population (because the high number of people who die are not being replaced by new babies)
• High Mortality Rate + High Birth Rate = stable population (because the high number of people who die are replaced by a lot of new babies)
• Low Mortality Rate + Low Birth Rate = stable population (because there aren't many people dying, so it doesn't matter that there aren't many babies being born)
• Low Mortality Rate + High Birth Rate = growing population (because there are a lot of new babies, but not many folks are dying to even things out)

 

The fact that we don't know the exact mortality rate or birth rate in this question is irrelevant. All that you need to know to answer the question is how it will cause change. If the same number of babies are being born, but less people are dying, this tells you that overall there will be more people living in the country at any given time.