Over-spending by Kublai .
Kublai 's successor caused them to resort to high taxes and extensive state monopolization of major sectors of the economy to fund their extravagant spending and military campaigns , which became a major burden on the Chinese economy .
Over-spending by Kublai and his successor caused them to resort to high taxes and extensive state monopolization of major sectors of the economy to fund their extravagant spending and military campaigns , which became a major burden on the Chinese economy .