Wealth inequality widened dramatically during the first two years of the economic recovery, as the upper 7 percent of American households saw their average net worth increase 28 percent, while the wealth of the other 93 percent declined, according to a report released Tuesday.

The study by the Pew Research Center underscored other data showing that the economic growth that has followed the Great Recession has benefited mainly those at the top. The uneven recovery has only accelerated a decades-long trend of growing wealth inequality in the country, despite rising popular and political awareness of the dynamic.

From 2009 to 2011, the average net worth of the nation’s 8 million most-affluent households jumped from an estimated $2.7 million to $3.2 million, Pew said. For the 111 million households that form the bottom 93 percent, average net worth fell 4 percent, from $140,000 to an estimated $134,000, the report said.

The changes mean that the wealth gap separating the top 7 percent and everyone else increased from 18-to-1 to 24-to-1 between 2009 and 2011. Overall, the most affluent 7 percent of households owned 63 percent of the nation’s household wealth in 2011, up from 56 percent in 2009.

The biggest difference between the most-affluent group and everyone else, Pew said, is that the wealthiest households have their assets concentrated in stocks and other financial instruments, while others’ wealth is concentrated in their homes.

See which groups had the biggest growth in net worth.

Both stock and home values were pummeled during the recession. But in the recovery, stock values have rebounded nicely and have reached new highs. Housing values — particularly for those living in nonexclusive areas — have stayed mostly flat, although there have been some stirrings of a recovery in the past year.

In the two-year period covered by the report, the Standard & Poor’s 500-stock index rose by 34 percent, while the S&P/Case-Shiller home price index slipped by 5 percent.

“It has been a very good recovery for those at the upper end of the wealth distribution,” said Paul Taylor, executive vice president of the Pew Research Center and co-author of the report along with Richard Fry, a senior research associate. “But there has been no recovery for the lower 93, which is nearly everybody.”

The wealthiest Americans were those most likely to own the financial assets that have done well in the recovery. They were 13 times as likely as other households to own government securities or municipal or corporate bonds. They were more than four times as likely to own stock or mutual-fund shares. And while almost two-thirds of households with at least $500,000 in wealth owned a 401(k) or Thrift Savings Plan, only 39 percent of those with less than half a million dollars in net worth owned one of those assets.

The report analyzes Census Bureau data, which were then compared with information sketching the wealth profile of American households, including the Federal Reserve’s Survey of Consumer Finances.

The picture that emerged is consistent with the growing economic polarization seen in income statistics, as well as in studies showing particularly slow growth in middle-income jobs since the end of the recession.

Overall, the report said, the amount of wealth held by Americans increased 14 percent between 2009 and 2011, going from $298,000 to $339,000 in inflation-adjusted dollars. Still, only the 13 percent of families with a net worth of $500,000 or more saw their wealth grow, the report said. Every other wealth group saw their net worth decline.

The issue of inequality leapt to prominence in late 2011, when supporters of the Occupy Wall Street movement began setting up encampments in Washington, Lower Manhattan and elsewhere to protest the financial chasm between the wealthiest one percent of Americans and the rest. And income inequality drew attention in the most recent presidential campaign, as President Obama railed against the growing economic divide. His Republican opponent, Mitt Romney, who made many millions as head of a private equity firm, was pilloried by Democrats as an uncaring symbol of that top one percent, as was his vice-presidential running mate, Rep. Paul Ryan (Wis.), whose budget proposal would have dramatically slashed spending on programs that help the poor and middle class.

Although Obama won the election, many of the tax and other policies aimed at addressing the complex causes of inequality have not been passed by Congress. Those that have become law so far have done little to close the gap.