Coca-Cola (NYSE:KO), the world's biggest beverage maker, has long been one of Wall Street’s barometers of the global economy. The U.S. company’s Q3 2013 results are living proof of what the International Monetary Fund advised in its last global growth predictions: developing markets are increasingly more volatile, which reflects multinationals -- including Coca-Cola.

The Atlanta-based soda giant registered a 3 percent year-on-year drop in its Q3, with earnings of $12 billion worldwide. When broken into regions, Asia and Africa fell 4 percent, and the Pacific region 9 percent. Europe grew 10 percent. And Latin America remained the same.

The results come as a surprise -- the Q1 2013 registered an increase of 4 percent in Latin America. Previously, Latin America was considered the main reason for the company’s growth; in 2011, for instance, Coca-Cola’s earnings in the region grew 13 percent.

What has changed? Between social upheaval, inflation and a commodity crisis, Latin America has had a rough year, which might have affected the world’s leading soft drink maker.

Mexico’s Crusade Against Sugary Drinks

Mexico had huge news this last summer: It lead the ranking of obese countries in the world, surpassing even the formerly undefeated champion, the United States. One-third of Mexicans are overweight -- a full percentage point over the number of overweight Americans.

To fight the trend, President Enrique Peña Nieto’s administration, which has had a very intense year of political reforms, included sugary drinks in the list of items that will have a tax increase. If the fiscal reform is approved, a liter of soda will go up a peso in price, from the current 12 pesos (90 U.S. cents).

While it's too early to blame the tax on drops in sales, Coca-Cola was one of the first companies to express concern over the measure. Mexico is the world's largest consumer of soft drinks, with 46 gallons of soda consumed by an average per person -- and an increase in price, however small, could pinch sales.

Venezuela Doesn't Need It (And Bolivia Might Not Need It Either)

It's not news that the late Venezuelan leader Hugo Chávez wasn't a big fan of the U.S. Chávez's incendiary speeches against capitalism and the northern neighbor were a common practice during his 14 years in power.

Indeed, during a 2011 speech, Chávez said that “Venezuela can live without Coca-Cola.

“Coca-Cola isn’t indispensable,” he said. “Who said it is necessary?”

Chávez's sentiment resonated again in May, when a strike paralyzed the Venezuelan Coca-Cola plant in the central-western city of Valencia, sending sales down 15 percent. The striking workers restarted the plant after 24 days, but their demand for better wages wasn't met and they were required to make up lost work hours.

Coca-Cola faced another challenge when Bolivian President Evo Morales announced plans to expel the company by Dec. 21, 2012, which is considered to mark the end of the Mayan calendar. Foreign Minister David Choquehuanca said the date also marks the end of capitalism and the start of a culture of life in community-based societies. And, Coca-Cola was to be banned in favor of mocochinche, a locally produced peach-flavored soft drink.

The Bolivian government later said that the foreign minister's words had been taken out of context and that it wasn't planning to ban Coca-Cola soft-drink products.

#BoikotCocacola, Or The Power Of Social Media

In this day and age, virtually no one is safe from scrutiny and our words are always with us. When Coca-Cola's CEO in Spain, Marcos de Quinto, made some comments labeled as a direct attack on a religious organization, Latin Americans didn't take it lightly.

In September, de Quinto made some comments construed as insentive about a Christian group called Hazte Oír, after the group asked the company to remove its ads from a controversial Spanish reality show. De Quinto reportedly called the group's followers “fanatics” and “intolerant.”

“May God spare from groups like ‘The Guardians of the Faith,’ who want to tell us what shows to watch, what books and newspapers to read, what party to vote for,” a Twitter post attributed to De Quinto said.

His remarks were taken as a direct attack on Christians, and it spurred an outcry in Latin America, the continent with the world's largest concentration of Catholics. The hashtag #boikotcocacola became a trending topic in Colombia, Ecuador, Peru and Panama, and thousands of Twitter users vowed to stop buying the products.

As the boycott spread across Latin America, Coca-Cola saw its share price drop 0.8 percent on Sept. 5, and Motley Fool contributor Amanda Alix called the decline “surprising” given the company's strong performance the previous day .