Since the 1950s, following wide-scale emigration from Calabria, the organization has established itself worldwide. The 'Ndrangheta is the only one of the Italian mafia-type organizations to have maintained its ancient rites, passing them down orally and through secret codes. It is characterized by a horizontal structure made up of autonomous clans known as ndrine, based almost exclusively on blood ties.  Its main activity is drug trafficking, on which it has a monopoly in Europe, but it also deals with arms trafficking, money laundering, racketeering, extortion, loan sharking, and prostitution. The 'Ndrangheta has enjoyed, for decades, a privileged relationship with the main South American cartels, which consider it the most reliable European partner. It is capable of heavily influencing local and national politics and infiltrating large sectors of the legal economy. In 2013 they purportedly made € 53 billion according to a study from Demoskopika Research Institute. A US diplomat estimated that the organization's narcotics trafficking, extortion and money laundering activities accounted for at least three per cent of Italy's GDP in 2010.