America’s biggest banks have become more concentrated in just two companies, while a third have become significantly less influential over the past two decades, according to a new study.
The findings were based on a survey of about 600 top executives from the biggest US banks.
They included those who had been at the company for over five years and those who left after only four years.
The study also found that the number of financial companies owned by four of the country’s largest banks has grown significantly over the last two decades.
In the decade since the financial crisis, four of America’s largest banking firms have become less influential.
The results of the study were published in the journal Nature Communications.
The study used a survey tool developed by Harvard Business School researchers that asks employees to rate the importance of each of the bank’s main financial services companies over the previous five years.
It is not an annual survey of the top executives at each bank.
The survey asked employees about their perceptions of the companies’ effectiveness and the likelihood that they would be able to influence the financial markets.
“This is the first time that we’ve been able to quantify the concentration of power in just one of the four largest financial services firms,” said lead author Jodi Cottam, a Harvard Business professor who led the study.
“They are very different from one another in their structure, but in their overall impact.”
The results show that the four biggest banks that are now more influential have grown significantly, and have significantly more financial services clients than the smaller banks that have remained relatively unchanged over the same period.
The four biggest US bank holding companies now control nearly two-thirds of all the banks that operate in the US.
The concentration of banks that dominate US banking has become so big that they now control almost two-fifths of all US stock market holdings.
The concentration of banking companies is more pronounced in some areas of the US economy than others.
Banks dominate most of the financial services industry, including mortgages, mortgages for companies and credit card issuers, and financial trading, according the report.
The US stock markets are dominated by banks, and many of those companies are also among the biggest owners of financial assets.
Cottam said the results showed that banks could have an outsized influence over US economic growth and financial markets without becoming too powerful.
“This has been a big story in financial policy over the years, and the problem is that it hasn’t been addressed in this study,” she said.
She added that it was possible to understand the concentration by looking at the financial assets held by banks and comparing it to their financial assets, which she called “corporate” and included securities, bonds, derivatives and other assets.
She said there were a number of reasons for this concentration, including the nature of financial services, the size of the firms’ balance sheets, the types of firms and their size, and other factors.
For instance, the concentration in financial assets is concentrated in the mortgage-backed securities market, where the biggest banks own about one-third of all mortgages.
However, Cottams study found that some of the banks had been less influential in recent years.
In addition, Cattam said, some of these financial assets that have been concentrated have become “highly leveraged” investments that can be viewed as risky by investors.
She noted that some firms, such as banks that offer loans, have also been “very leveraged,” which means they are able to take on large amounts of debt.
Other financial assets like mortgage-based collateral have become increasingly attractive for investors, which has made some banks more likely to become more powerful in the market.
As the concentration grows, the financial sector is likely to continue to have a big impact on the US economic system, she said, but she noted that the concentration itself would be difficult to predict.
“These firms are very complex, they have been around for a long time, and it will be difficult for us to predict what they’ll do.”
Cattam and her co-authors said their research was a reminder of the importance for the public to know who owns the banks they use to invest in.
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