He foresees a major shift, especially on energy, since nuclear power accounts for 30% of Japan's total.

"If it was only the tsunamis, Japan would be able to manage [a recovery] quickly. But the nuclear leaks have diminished the confidence in nuclear technology," he said, noting that this remains the case even though Japan is an exporter of nuclear reactors and has advanced technology in the field.

Therefore, Japan is likely to relocate its manufacturing bases, including high-technology industries, because of rising costs and labour shortages, while the strong yen will also help it reduce the costs in other countries.

In addition to its ageing population, which is resulting in a shrinking workforce, Japan faces physical constraints. The country has 127 million people but of its 380,000 square kilometres, 80% are mountainous areas that cannot be used as arable land.

"Japan has to adjust its strategy economically and also consider the relocation of people," said Dr Sompop.

He predicted that Japan would look toward countries in Southeast Asia as people in this region have positive attitudes toward Japanese people.

Thailand could be the first or second priority, he said, as Bangkok now has the third largest Japanese expatriate population in the world after New York and Shanghai.

Dr Sompop also sees the possibility of more elderly or retied Japanese people moving to Thailand in search of a better quality of life, a low cost of living, and lower risk of natural disasters. This could open new opportunities for Thai service businesses.

Looking at infrastructure development in Asean in the long term, he said Japan might invest more to create a regional supply chain in Asean countries, which will help economic development.

As well, he said, Japan may seek to use more biofuels, creating demand for energy crops.