School sixth forms, sixth form colleges and further education (FE) colleges funding fell by 16 per cent between 2010/11 and 2018/19.
The real-terms cuts are double the rate seen across the schools budget, which fell by 8 per cent between 2009/10 and 2017/18.
Independent research body the Education Policy Institute (EPI), which produced the report, 16-19 Education Funding Trends and Implications, is calling for the government to review the cuts and assess the impact on disadvantaged students.
The report, commissioned by education think-tank Pearson, found that school sixth forms saw the largest cuts in this age bracket.
Funding plummeted 26 per cent from 2010/11 to 2018/19, while in sixth form colleges and FE colleges, it fell by 18 per cent.
The analysis finds that FE colleges have experienced smaller cuts than sixth form colleges. This is because FE colleges tend to attract more disadvantaged students and funding has increased to compensate providers for this challenging demographic.
However, the report warns, student support has fallen dramatically and disadvantaged students do not seem to be attending provision where learning hours have been protected.
On average, real-terms teacher wages in further education colleges fell by 8 per cent between 2010/11 and 2016/17 from £33,600 to £31,000.
Teacher wages in further education colleges are 17 per cent lower than in secondary schools (£36,700).
The fall was less acute in sixth form colleges, where the average teaching wage decreased from £39,900 to £39,000.
The report states that there is a "scarcity of evidence of whether the decline in 16-19 funding has exacerbated the gaps between disadvantaged students and their more affluent peers".
It adds: "The government should review the impact of funding changes on disadvantaged young people and ensure that future funding policy works to close the disadvantage gap."
The overall financial health of 16-19 providers has been hit, with the proportion of those with in-year deficits increasing across all institutions since 2010/11.
This is particularly the case in sixth form colleges, where the rate rose from 7 per cent to 36 per cent between 2010/2011 and 2016/17.
An increasing number of local authority schools with sixth forms are in financial difficulty - the proportion with cumulative deficits has risen from 12 per cent in 2010/11 to 22 per cent in 2017/18.
The rate at schools without sixth forms rose from 6 per cent to 9 per cent.
In addition to the funding squeeze, students are receiving fewer hours of learning with a teacher - it fell by 9 per cent across all institutions between 2012/13 and 2016/17.
This fall was particularly prominent in Level 3 subjects (A-level or equivalent), which saw a 21 per cent decline in hours.
For academic subjects, there has been a large decline in AS provision, which has not been offset by rises in the number of hours elsewhere.
The report notes that the deterioration of 16-19 institutions' finances may exacerbate these trends and raises concerns about the curriculum narrowing.
However, the report's authors said there is no clear relationship between the squeeze in funding and Ofsted ratings of 16-19 providers.
David Laws, executive chairman of the EPI said: "It is not clear why successive governments have chosen to squeeze 16-19 funding, and there is a strong case for reviewing the adequacy of funding before the upcoming Spending Review.
"The government should also consider if enough is being done to support disadvantaged students, who are disproportionately concentrated in FE colleges, where teacher pay is significantly lower than that in school sixth forms."
Kevin Courtney, joint general secretary of the National Education Union, said that the report "shows that the cuts have fallen hardest on the most deprived students".
"The government must act to reverse this as a matter of urgency. It is clearly wrong that 16-19 students receive less funding than secondary students and less than half the amount spent on higher education.
"The current situation is unsustainable and must be addressed immediately."