Of the big five European leagues, France and England offer the most stable environments for coaches at 24 months, followed by Germany (22), Italy (19) and Spain (11).
Northern Ireland provides the greatest hope for survival in Europe with coaches remaining an average of 86 months in the same post, according to the report released on Thursday.
The study, based on coaches in place at 624 top-flight European clubs in November, found that all 18 in Greece at the time had been in their jobs for less than one year.
Georgia and Romania were little better, with coaches lasting five months. The average survival time was six months in Cyprus, Faroe Islands and Macedonia.
Following Northern Ireland as the most stable countries were Finland (54 months), Norway (31), Iceland (30) and Sweden (28).
"Everyone involved in football wants to win," said UEFA secretary general Gianni Infantino in a statement.
"But when we look at the last three years of club football and see almost 2,000 head coach changes and combined club losses of more than 127;4bn, it is clear that the football family needs more stability, less short-term thinking and better financial sustainability."
A second study found there were 1,700 coaching changes among Europe's approximately 700 top-flight clubs between mid-2010 and mid-2013.
"Frequent head coach changes (often accompanied by changes to backroom staff) can have an impact on both sporting and financial stability," said the report.
There were "clear cultural differences between the north and the south-east of Europe".
- Sports & Recreation