Soaring beer prices and rising rents have been blamed for a huge number of pubs changing hands in recent years.
The GMB union said the level of business failures and increasing debts in the industry was high because of "unrealistic" rents as well as the price of beer.
Research into 8,400 pubs run by Punch Taverns showed that 2,600 had changed hands in the past three years mainly because of leases coming to an end, tenants giving notice, business failures or repossessions, said the union.
The report follows an earlier study by the GMB highlighting the number of pubs closing across the UK.
Paul Kenny, general secretary of the GMB, said: "A lot of tied pubs no longer have regular tenants. This GMB analysis shows at least a 32% 'churn' in the Punch estate.
"This high level of churn is not unique to Punch and will be replicated in other pubco estates. The churn shows that the number of closures in the big pubcos are the very thin end of the uneconomic wedge in this sector and that the level of business failures is high because of unrealistic rents and wholesale beer prices charged by pubcos."
The union said publicans were being overcharged by up to 80p a pint as well as facing increased rents, which was "driving them out of business".
Steve Corbett, a member of the Fair Pint Campaign, said: "For too long the pubco bosses and their trade representatives have been hiding the damaging level of pub failures in their estates.
"These figures from GMB will be all too familiar to those inside the pub sector but hopefully they will come as a shock to MPs and business leaders."