Answer:
I would say famine and lack of land.
Step-by-step explanation:
I'm not 100 percent but if the pull factors are jobs and land that means they are struggling to find/keep jobs were they are (meaning they wouldn't have money of food = famine) and they do not have the amount of land they want. These things would push someone out of where they are now to find somewhere where they can have what they want/need.
I hope that makes since.