TOKYO — Despite low voter turnout, the governing party of Prime Minister Shinzo Abe won a landslide victory in parliamentary elections held Sunday that position Mr. Abe to remain Japan’s leader for several more years.

The question, political analysts say, is what Mr. Abe will do with his renewed mandate.

When the prime minister called the snap elections last month, he proclaimed them a referendum on his economic-revival policies, known as Abenomics. The policies appeared to be losing steam recently after initially lifting the long-stagnant economy when Mr. Abe took office two years ago.

During the elections, however, he remained vague on what he would do to breathe new life into Abenomics — policies that have so far amounted to little more than pressing the central bank to flood the economy with cash. Now that Mr. Abe has won a convincing victory, he and his party face the hard part: actually delivering on those promises to engineer a more lasting recovery.

Economists have called on Mr. Abe to follow through with promised changes to open Japan’s still-protected markets to greater competition — such as by making it easier for young Japanese to create start-ups — and to more trade and foreign investment.