The economic and political similarities between classical China and India are that they are both agricultural societies and both empires divided their land into smaller city-states, while the differences are that India focused more on trade than China, and the Chinese government followed Confucius instead of India’s Buddha. Both societies had a strong agricultural base to them. The agricultural way of life is, after all, what led them to become the great empires that they were during that time.
This economic similarity meant that the people stayed basically in the same place and farmed the land and domesticated animals. Not to say that there were no nomadic herders in the empires, but they stayed on more of the outskirts and were greatly outnumbered. Both empires also had many city-states within it. Back in the day, there was no technology so news traveled pretty slow, so it was much easier to just have aristocrats under the king’s(or emperor’s) rule make all of the small decisions and be in charge of their allotted land.
In China though, this kind of backfired by the aristocrats having too much power. They overturned the king and there was a period of chaos before the Qin Empire was established with harder rule over the new beurocrats. There were also some differences between the empires. For one, India’s economy was more greatly influenced by trade than China. This was partly just because of the geography. China was basically separated from the other side of the Himalayas so the only way that they could get to places like the Mediterranean and Middle East was through India or actually across the Himalayas.
Also, China was basically producing everything they needed so the only reason they traded was for revenue. India on the other hand, had access to the Indian Ocean and flat land that connected them to the Mediterranean and Middle East. The Chinese government had Confucius, the powerful founder of the way of thinking that led the people of China to seek Dao (or the way). India, on the other hand, had the religions of Hinduism and Buddhism that taught their people to seek their dharma.
The Confucius way of thinking was originally developed as a political system to govern the state but gradually moved to teach not to care about money, possessions and more on your place in reincarnation. The Hindus believed in caste systems and to stay in your place within the system. The Buddhist religion sort of supplemented it by saying that it was good to know your place, and while striving to achieve a better life, remember your place and how to do your part within your place.