The phrase "to sustain the economy" means to support and maintain the overall health and growth of a country's financial system and businesses. Full definition
No doubt, our manufacturing sector will be sustaining our economy in two hundred years when our oil and gas reserves are gone. (canadianbusiness.com)
Some small island states are now trying to restore once - rich ecosystems while sustaining their economies. (dotearth.blogs.nytimes.com)
The other factor sustaining the economy of Billings» 100,000 residents is its place as the largest industrial and transportation hub and a major retail center for a wide geographical area. (localresumeservices.com)