为什么不是国家2而是国家3

问题如下：

An economist gathers the following historical information on select economic variables:

Based only on this information, which country is most likely to forecast the highest potential sustainable rate of economic growth?

选项：

A.Country 1 B.Country 2
C.Country 3

解释：

A Incorrect because Country 3 is most likely to forecast the highest potential sustainable GDP growth rate. Country 1 has a higher share of the population over 65 than does Country 3.

B Incorrect because Country 3 is most likely to forecast the highest potential sustainable GDP growth rate. Country 2 has a higher share of the population over 65 than does Country 3.

C Correct because Country 3 is to forecast the highest potential sustainable GDP growth rate. Demographic factors (i.e., the number of workers available to enter the workforce) can positively or negatively contribute to a country’s sustainable rate of economic growth.

Country 3 (compared to Country 1 and Country 2) has the highest share of the population under the age of 16 and the lowest share of the population over the age of 65. Over the next decade, Country 3 will receive a demographic benefit because of the high percentage of young people entering the workforce. All else being equal, this implies higher growth of the labor force and hence higher growth of potential GDP.

From an historical point of view, the population growth rates of Country 1 and 2 (mainly driven by net migration) were slightly above the population growth rates of Country 3. However, a high pace of immigration for Country 1 and 2 is not sustainable and is likely to slow, which will result in slower growth in both the population and the labor force.

In sum, the lack of (potential) population growth and a rapidly aging population in Country 1 and 2 will limit their potential rate of growth. Potential GDP growth in Country 3 should receive a boost from its favorable population trends.