Wealth accumulation is slowing in North America relative to other regions of the world, according to a new report from Boston Consulting Group. The growth rate of affluent investors’ assets under management in North America—4.1 percent in 2005—lagged behind Europe (13.2 percent), Asia-Pacific, Japan, the Middle East and even Africa and Latin America. The global average in 2005 was 8 percent. North America’s growth slowed from 7.3 percent in 2004.

The report, Taking the Client’s Perspective: Global Wealth 2006, attributed the drop to a declining savings rate and weaker stock market in the United States. The latter proved particularly damaging because equities account for more than half of the average investment portfolio in the U.S. Boston Consulting attributed the robust European growth rate to the strong economic performances of countries such as Germany, where the stock market grew by 27.1 percent in 2005.

However, North America remained the largest wealth market, with $33.2 trillion in assets under management. The United States also claimed more millionaires than any other country. The number of millionaire households—those with greater than $1 million in assets under management—reached 7.2 million worldwide last year; approximately 41 percent, nearly 3 million, of those were in the U.S.

Japan had the second-largest number of millionaires, with 825,000, followed by the United Kingdom, Germany, France and China.

The United States also boasted seven of the 10 cities with the highest populations of millionaires. New York ranked first with 490,000.

Boston Consulting, a private firm, used a proprietary model to estimate the size and growth of the wealth markets, and interviewed and surveyed wealthy investors for further insight into client behavior for the report.

—Andrew Farrell