Based on a survey of messages left online and at the scenes of executions, Eduardo Guerrero, a Mexican academic, estimates that in 2007 there were 11 organised-crime groups active in Mexico, whereas in 2010 there were 114.
Amir Attaran, another Harvard academic, estimates that the volume of DDT used to protect the entire high-risk population of Guyana for a year is equivalent to what a farmer might spray on to a single field of cotton.The treaty drafted in Johannesburg, which is due to be signed in May, is a welcome antidote to this nonsense.
But some advocates and academics estimated the amount of money owed now, including interest, could be $500 million or more.
Some NGOs and academics estimated there may be up to several hundred thousand Christians practicing their faith underground in the country.
Last year, three academics estimated that on a moonless, clear night in an urban area, without any buildings or trees in the way, a person might see 1,100 stars.
In 2012, two academics estimated that spammers earned about $200 million annually, which was dwarfed by the $20 billion spent in the U.S. to fight it.
In the mid-1990s, a group of academics estimated that the turnover of Thailand's sex and gambling industries amounted to more than 10% of GDP.
The academics estimated the scheme could cause a one-off rise of between11% and 2% in retail power bills, but subsequent modelling by Reputex found the impact could be even lower – between 0.2% and 1.3%.
Academics estimate that better use of waste resources could save Europe €600bn by 2030.
