The BBC News website has been speaking to Zimbabweans who have left the country in recent years about their reasons and the risks they took. Justin Pearce looks at the reality behind the emigration figures.
Emigration has become a way of life in Zimbabwe - so much so that the International Organisation for Migration has started a campaign specifically to advise and help those considering to migrate.
Significantly, the IOM has done so with the co-operation of the Zimbabwe government, which tacitly admits that its citizens are leaving en masse.
So where are all the people going?
Figures published by the IOM suggest that the largest group of legal emigrants - 36.8% of the total - go to the United Kingdom, while only 4.8% go to South Africa.
These figures represent the numbers of people who have emigrated from Zimbabwe using official channels since 1990. In total, the figures suggest about 500,000 have left in 15 years.
But anecdotal evidence and common sense indicate that these figures for legal migration give a skewed idea of the whole picture.
The Zimbabwe Central Bank said 1.2 million Zimbabweans had gone to South Africa since 1990.
A South African government minister recently said there were two million Zimbabweans living in South Africa - Joyce Dube of the South African Women's Institute for Migration Affairs estimates the figure to be even higher, around three million.
"Go from the Limpopo to Cape Town, and you will find Zimbabweans in numbers," she says.
Other observers cast doubt on these figures - after all, South Africa's population is around 40 million, so two million Zimbabweans would mean five percent of those people were actually Zimbabweans.
Still others prefer not to fix a number.
"We'd hate to quantify, because of the xenophobia caused by talk of opening the floodgates of immigration," says Abeda Bhamjee, a refugee lawyer at the University of the Witwatersrand Law Clinic in Johannesburg.
However unclear the numbers, what is clear is that Zimbabweans who go to South Africa or neighbouring Botswana are much more likely to disappear from the official statistics.
Rather than seeking a work permit and getting on a flight to Europe or North America, they simply slip across the border - often doing so again and again after being caught by the South African authorities.
"They are deported, then the next day they are back," Joyce Dube says. "Deportation is a waste of money."
Why are Zimbabweans leaving in such numbers?
Until recently, one important reason has been that there is more money to be made elsewhere.
Skilled public servants in Zimbabwe have seen their wages rendered almost worthless by runaway inflation.
The Southern African Migration Project (SAMP) did a study on health professionals leaving Zimbabwe in 2002, and found that economic factors were cited by the greatest number of migrants (54% of the interviewees) as their reason for leaving Zimbabwe.
Around 30% pointed to professional reasons such as inadequate working conditions, and a similar number said political considerations had been a factor in prompting them to leave Zimbabwe.
Since 2000, a further economically important group of migrants has been white farmers - government policy changes led to the seizure of 4,000 white-owned farms, and many who lost land sought new opportunities elsewhere in Africa or overseas.
But far greater numbers of Zimbabweans felt the heavy hand of government with the launch this year of Operation Murambatsvina, the urban clean-up that the UN says left 500,000 people homeless.
Joyce Dube confirms that Murambatsvina has been a further reason for Zimbabweans to flee to South Africa - and she believes that these days, around 80% of the Zimbabweans who come to South Africa are leaving their country for political reasons.
For Zimbabweans who lack the professional qualifications that would secure them a ticket and a visa to get overseas, South Africa and Botswana are the obvious choices.
The recent clean-up campaign left 500,000 homeless
While these neighbouring countries have absorbed a number of Zimbabwean professionals, the majority of cross-border migrants are unskilled labourers.
"The official policy is that no one should be denied the opportunity to apply for asylum," Abeda Bhamjee points out, but adds that there are "internal and external pressures" on South African officialdom to keep Zimbabweans out.
The ease of access from Zimbabwe to South Africa makes officials wary of setting a precedent in granting asylum to Zimbabweans.
Moreover, acknowledging that Zimbabwe's internal problems warranted granting asylum to its citizens would contradict President Thabo Mbeki's policy of "quiet diplomacy" towards his northern neighbour.
The result: more Zimbabweans invisible to the official statistics.
Attempts to number the new arrivals are further complicated by the fact that, as far back as colonial times, there has always been a flow of people between Zimbabwe and its neighbours.
"With migrant workers there has always been a relationship, especially with southern Zimbabweans," recent migrant Mlalumi Nkomo points out.
"Zimbabweans have always been part of South African life."
Will the Zimbabwean diaspora ever go back? SAMP's research indicates that Zimbabweans are reluctant to cut ties with their homeland.
A study of final year students in Zimbabwe revealed that while many were considering seeking employment abroad, less than one-third would give up their homes in Zimbabwe, and barely a quarter would be prepared to renounce their Zimbabwean citizenship.
Those who fail to secure legal status and decent employment abroad are most likely to return to Zimbabwe as soon as circumstances there improve.
Those who have already established themselves professionally seem more ambivalent.
"I want to retire in my early 50s - when I am still strong enough to go back and reintegrate into society," one Zimbabwean health professional, now working in the United Kingdom, told the BBC News website.
"Until then we will continue to go home on holiday every two years, to keep the ties alive and so that we remain recognisable to those we left behind," he added.
But for those who have legalised themselves in other countries, the longer they stay, the more entrenched they will become in their adoptive homes.
"There's nothing compared to being back at home but for now it is the last place I could think of being," says Constantine Mkinya, a lawyer who has settled in the United States.
"I'm very happy with my life here in America."