The IFS has also found that the raising of the retirement age for women has strengthened the UK economy by £2.1 billion in just under three years.
The employment rate among 60 year-old women has increased from when the retirement age began to rise in 2010 and in April 2012 was 51.4%.
In April 2010, the state pension age for women was increased from 60 to 61. The study looked at those women who just missed out on claiming a pension as a result of that change.
It found that employment rates within the 60 year-old age group increased by 7.3%, resulting in 27,000 more women continuing to work.
However, the figures show that another 5,000 women would also have liked to continue to work, but were unable to find jobs. That resulted in a 1.3% increase in the number of women aged 60 who were unemployed.
Jonathan Cribb, a co-author of the report, said: "Increasing the age at which women can first receive their state pension has led to significant numbers of women deferring their retirement, with over half of women aged 60 now in paid work for the first time ever.
"We also find that some husbands are responding by remaining in work for longer."
Cribb added: "This is initial evidence that raising pension ages can have significant positive effects on employment."
Joanne Segars, chief executive of the National Association of Pension Funds (NAPF), said: "The IFS research is intriguing.
"Many men and women might be delaying retirement because they want to keep working, or because they need the money. Some might be trying to postpone turning their pension pot into an annuity while rates are so poor."
Segars said that more than half of workers have told the pensions body that they expect to keep working beyond the state pension age because they will not be able to afford to retire and said it is "essential" that people plan their retirement saving.