About 73 million US households now have discretionary income, up from about 57 million in 2002, according to a report by The Conference Board. The proportion of the US population with discretionary income has increased to nearly 64%, up from 52% in 2002.

Households with discretionary income, as defined by the study, are those whose spendable income exceeds that held by households with similar demographic features.

Total discretionary income in the US topped $1.7 trillion in 2006, with the household average at $24,335. Per capita income stood at $9,148.

“While the percentage of households with discretionary income has risen over the past several years, purchasing power remains concentrated in the wallets of the affluent,” said Lynn Franco, director of The Conference Board Consumer Research Center.

Nearly 78% of all discretionary income is held by households earning more than $100,000. Average discretionary income for this segment, $66,451, is 2.7 times the national average.

Below, some highlights of The Conference Board report:

Top regions

The region with the wealthiest concentration of households is New England (including Connecticut, Massachusetts, Maine, New Hampshire, Rhode Island and Vermont). About 63% of households have discretionary income, with an average amount of $27,337.

Household discretionary income is lowest in the West North Central region (including Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota and South Dakota). Average household discretionary income in the region is $20,749.

Top states

California, the most populous state, is also the state with the largest number of households with discretionary income: 8 million. These households hold $224.7 billion in total discretionary income.

Texas has the second-highest number of households with discretionary income – more than 5 million, with $136.8 billion in total discretionary income.

Other top states are Florida, with almost 4.7 million households holding $126.1 billion, and New York, with about 4.6 million households holding $119.4 billion in discretionary income.

Other findings: