What influence did the northerners' southward migration have on the economic development of Jiangnan area during the Eastern Jin Dynasty and the Southern Dynasties?

I think the most important thing is to bring enough population and provide enough labor for the development of agricultural economy in the south of the Yangtze River. On the other hand, it is technological progress, which is also a very important aspect. Judging from the situation at that time, the most important thing was a progress in agricultural technology, which was very important for the development of agricultural economy in Jiangnan.