The move comes amid fresh questions in some quarters, including from some Eurosceptic parties such as Ukip, about the cost effectiveness of the agencies.
The agencies, which are generally involved in executing or enforcing EU policy, have converged in Parliament for a two day gathering.
The studies said the agencies make a "vast contribution to the economic and political development" of the EU.
The EU Agencies Forum was told that that while the agencies represent less than 0.8 per cent of the EU's annual budget, their contribution has "widespread impact at citizen, industry and policy level."
One study analyses the cost-effectiveness of the seven agencies operating to support the internal market and "how they reduce the overall costs to taxpayers."
António Campinos, executive director of the EU Intellectual Property Office (EUIPO), which is currently Chair of the EU Agencies Network, was among the speakers.
He said, "The agencies are the familiar face of the EU for many Europeans, delivering essential services on the ground for a relatively small proportion of the overall EU budget - less than 0.8 per cent, to be exact.
"In other terms, they cost €1.23 per EU citizen. The cost-benefit ratio is hence very positive, and as these studies show, EU agencies save national administrations many millions every year by preventing duplication of efforts in each member state."
However, Ukip MEP Julia Reid MEP countered by saying, "Reagan's phrase 'Government is not the solution to our problem; government is the problem' seems a fitting quote.
"This is a report which is filled with self-congratulations and praise over how many unnecessary European agencies exist. Why don't we start following Reagan's advice and start cutting some of this waste instead of watching eurocrats pat each other on the back?"
Campinos told the forum that the agencies "create significant efficiencies and deliver value for EU citizens across a wide range of policy areas."
One of the two reports was commissioned by the European Parliament and estimates that it would cost member states up to €200m a year to assume the tasks currently done by just seven of the 45 agencies.
The forum heard the agencies "play an important role" in many aspects of citizens' lives, including disease prevention and control, security and defence, education and knowledge and stability of the financial systems.
Several agencies were highlighted for their work, including Frontex, the European border and coastguard agency, which currently deploys some 1200 officers at EU's external borders and has, it was said, helped to rescue more than 89,000 people at sea so far this year.
The European Asylum Support Office, meanwhile, currently deploys over 300 staff in around 20 locations in Italy and Greece. The forum was told that it is working to support the implementation of the EU relocation programme.
Elsewhere, Europol, the EU's law enforcement agency, was said to have supported more than 40,000 investigations against terrorism and serious crime.