There are two practical reasons why Pakistan has a greater population growth rate among other nations.
Also Read: A Pakistani Man who has 34 kids
1) ReligionPakistan is an Islamic country where more than 97% of the population is Muslim. Islam gives luxury to produce as many children as one can. Additionally, it is also allowed to Muslims to marry up to 4 women of their choice, which further is a factor behind more kids.
2) LifestyleAbout 70% of Pakistanis live in rural areas where most of them are engaged in the business of agriculture. Many have their own acres of lands and it very likely to have disputes over lands in rural areas. Since law and order is not much efficient in rural areas, so, to manage control over their lands, they need trust worthy people, and the only way for them to have trust worthy people is having their own kids.
So, since their life style has made more kids their need, and their believe system also allows them to do so, it is quite normal for rural Pakistanis to have as many kids as they desire.