However, it has resumed its international diversification in the 21st century, and today its products are sold worldwide.
Until the late 1990's, many people in academia and on Wall Street said international diversification provided a free lunch.
THE study did not address the argument that international diversification is no longer important because so many companies are multinational.
One possible disadvantage of bond index funds is that they do not allow for much, if any, international diversification.
Professor Singal says he believes that a big reason for this trend is the increase in international diversification among the largest companies.
In the 1970's, he said, fewer American companies enjoyed the immunity that international diversification confers.
Capital flows can help developed countries achieve a better international diversification of their portfolios.
But it turned out that there was little safety to be found from international diversification.
Franklin also promotes the international diversification its fund provide.
The professors' findings do not justify the elimination of international diversification.