“The reason these studies are often criticized is it’s not clear how they produced these calculations,’’ she said. Amberg is a co-author of a 2011 report that begins with the line: “Economic impact analyses for universities often produce impacts that are so large they are viewed with suspicion.”

Economist Lon Hatamiya produced the UM analysis, and said he used a conservative approach in estimating spillover spending by UM in Broward, Miami-Dade and Palm Beach counties. Among the assertions in the report:

•  By spending about $62 million on construction in 2011, UM added about $200 million to the economy.

•  Despite a payroll of 13,000 people, UM supports roughly 40,000 jobs throughout Miami-Dade County alone as businesses and contractors benefit from the university’s spending.

•  The report notes that a $6 billion annual economic impact would be 18 times as large as the economic impact claimed by the NFL when the 2010 Super Bowl came to Sun Life Stadium (part-time home to the Miami Hurricanes). A study funded by Super Bowl organizers estimated the game generated $330 million for the local economy, though Porter and others criticized that figure as inflated.

Hatamiya, owner of a Northern California public-relations and economics firm, performed the analysis for Bendixen & Amandi, the Miami research and communications firm that UM hired for the report. A previous report, commissioned by UM in 2007 before it purchased the former Cedars Medical Center hospital, claimed a $4.5 billion economic impact.

The report comes during a sensitive time for UM, as it negotiates a new contract with Miami-Dade over the more than $100 million the county pays UM as part of its Jackson agreement. Financial records also show financial pressure for UM, the county’s second-largest private employer, with the last budget year ending with a $28 million operating loss. Natoli said severance costs related to the roughly 800 lay-offs in the spring contributed to the deficit.

The lay-offs were not mentioned when UM presented the report to a meeting of business executives Monday morning at the Beacon Council, Miami-Dade’s economic-development agency. The presentation centered on UM’s positive contributions to the local economy, despite the severe recession.

“To rename this county ‘University of Miami-Dade County’ would not be inappropriate,’’ said Fernand Amandi a partner at Bendixen Amandi.