In a note to clients this week, Goldman Sachs analysts led by Robert D. Boroujerdi look at merger trends in various industries.

One that has gone through substantial consolidation in the last 10 years is the global beer industry.

Here's Goldman:

The global beer industry has undergone a steady process of consolidation. Ten years ago the global beer industry was highly fragmented with Anheuser-Busch’s 8.5% market share enough to make it the global leader. Since then, a steady process of consolidation via M&A has taken place – often focused around cost-cutting opportunities (e.g. the $60 bn merger of Anheuser-Busch and InBev completed in 2008) or geared towards acquiring attractive emerging market assets (e.g. Heineken’s $24 bn acquisition of Asia Pacific Breweries completed in 2012).

Today’s AB InBev, with an estimated 21% market share, has been the driving force behind much of this consolidation. Interbrew’s acquisition of AmBev in 2004 created a new global leader, InBev, with 11% share and the subsequent Anheuser-Busch/InBev merger in 2008 again created a global leader, AB InBev, with 20% market share. Today’s top 5 companies represent more than 50% of the global market (versus 32% for the top 5 players in 2003), and the industry’s HHI has risen to 725 in 2013E from just 276 in 2003.

"HHI" stands for Herfindahl-Hirshman Index, a common measure of industry concentration.

"The U.S. Department of Justice generally considers HHI levels of 1,500-2,500 to be consistent with moderately concentrated markets, and levels above 2,500 signifying high concentration," explain the Goldman analysts.

"The score is calculated as the sum of the squares of the market shares of an industry’s competitors."

In 2013, the global beer industry's HHI was 725 — almost three times what it was 10 years ago, but still well below the levels cited above.

"Global Beer measures as considerably more fragmented than the other industries in our study," say the Goldman analysts.

"The market for beer brands more often tends to be local than global, making it not directly comparable with the HHI scores of other truly global or purely local markets in this study. In the case of our beer study, the direction of the HHI is much more pertinent than the absolute level."