Japan's population is declining, deflation has returned, and the nation's economy is still stuck in cycle of weak, stop-start growth. And yet, there are a number of hidden and underutilized resources that Japan could tap to try to escape this economic malaise.

The Organization for Economic Co-operation and Development (OECD) notes that while demographics are against it, Japan still has a huge wealth of human capital, thanks to its highly trained and educated people. There's also dormant capital and even unused inventions that could be put to work to increase growth.

Japan was the world-leader in numbers of patents issued in 2014, according to the World Intellectual Property Organization, with almost 300,000 patents. The U.S. was second with almost 260,000 and China was third.