If the Bank of Japan wants to reach its 2 percent inflation target, policymakers may find more success in helping the typical grandparent remain employed rather than simply pumping monetary stimulus into the economy, according to economist Naoyuki Yoshino, who heads a government-affiliated think tank.

Yoshino explained that while monetary policy in Japan has contributed to pushing up wages among the working-age population, structural reforms are more important to achieve inflation because the effectiveness of monetary policy has reached its limits.

"We have to get elderly people back to work. Monetary policy only affects the working population, and not those that are retired," said Yoshino, dean of the Asian Development Bank Institute. "If we look at the data we see that retirees' consumption is smaller compared to working people. That is why the BOJ's inflation target cannot be achieved," he said in a recent interview.

A 2014 study commissioned by the Cabinet Office's Economic and Social Research Institute found that household expenditures usually decline after the main breadwinner retires.

"The BOJ governor should address politicians and point out that Japan's main problem is structural; it cannot be solved through monetary policy or fiscal policy alone," he said.

Yoshino, who earned his doctorate in economics at Johns Hopkins University in Baltimore, sees reforming the labor market as an opportunity to both improve productivity and help keep the elderly in the workforce.

In Japan, many workers are forced to retire at age 60, which is a byproduct of the seniority-based system of pay where older workers often receive salaries that are disproportionately high to what they produce. Companies are thus usually keen to remove such workers' high wages from their books.

"Introducing a productivity based wage rate is important. Those with higher productivity should receive a higher pay, with the exception that minimum wage remains in place. This will make companies more productive and also prevent them from pushing out workers as soon as they turn 60," he said.

Whereas some observers see structural obstacles as insurmountable, Yoshino differs from other BOJ naysayers in that he believes the 2 percent inflation target can be achieved even in a society when a large percentage of population is over the age of 60.

"If older people are working in the labor force, I think 2 percent inflation is attainable," said Yoshino, who has held the top post at the Tokyo-based institute since 2014.

While convincing workers to forgo retirement age seems like a monumental task, some data have in fact shown the willingness of seniors to continue their careers.

According to a survey in 2017 by the Cabinet Office, around 80 percent of elderly respondents want to work till they are at least 70.

"The textbooks say that most problems can be solved with fiscal or monetary policy. But Japan is not a textbook case," said Yoshino.