What factors can lead to the development of mixed economies?

A mixed economy means that part of an economy is managed by the government while part of it is left with the free market. Its development factors involve allowing private enterprise to run most of the business and then in the later part government can come in for providing public services or regulation of private business etc. 

2686-2181 bce-- "egyptian civilization developed along the nile river in large part because the river’s annual flooding ensured reliable, rich soil for growing crops."

1069-664 bce-- "ancient egyptians developed wide-reaching trade networks along the nile, in the red sea, and in the near east."

whats the question? im not quite understanding your question.