A catastrophic 7.0-magnitude earthquake struck Haiti two years ago, killing between 200,000 and 300,000 people in one of the worst natural disasters of modern times.

Despite a massive international aid effort, the poor and dysfunctional Caribbean nation of nearly 10 million is still struggling to get back on its feet. Here are some of the main reasons why:

THE AID MONEY: Of $4.9 billion pledged in 2010 for quake reconstruction, only about half had actually been received and disbursed when the UN revealed its figures in September.

The mandate of the Interim Haiti Recovery Commission, the body created to help direct the international aid and chaired by former US president Bill Clinton, ended in October and may not be extended by the Haitian parliament.

NGO STATE: Many donors prefer to channel money through the non-government organizations as they fear they will otherwise feed a bottomless pit of official corruption and incompetence.

NGOs have consequently ended up running key sectors such as schooling and hospitals, while the longer-term priority of addressing the government's infrastructural shortcomings has been neglected and coordination is lacking.

Haitian officials voice fears the country is turning into a republic run by NGOs -- estimates of how many operate in the country reach upwards of 12,000.

POLITICAL UNCERTAINTY: Deadly riots in December 2010 following the publication of the results of disputed first round presidential elections provided a grim reminder of Haiti's long history of political turmoil.

The return of former dictator Jean-Claude "Baby Doc" Duvalier and of his nemesis Jean-Bertrand Aristide, the country's first democratically elected president, threatened to open up old divisions and sow further discord.

Michel Martelly, a former carnival entertainer and pop singer, was sworn in as the new president in May 2011 with a clear mandate, but old resentments bubble beneath the surface and political upheaval could quickly return, especially if desperately needed progress is not made.

BOOMING POPULATION: One of the biggest problems facing Haiti is basic demographics. Despite one of the highest infant mortality rates in the world, the population is booming by almost two percent each year.

Four in 10 Haitians are under the age of 14. Most of the population lives on less than a dollar a day, 70-80 percent is unemployed and average life expectancy hovers around 30.

Port-au-Prince's estimated population of three million is expected to double over the next 15 years. Haitians are drawn to the capital to escape poverty but most end up in sprawling slums.

Haiti would likely benefit from having several smaller growth poles rather than a single, swollen metropolis.

LAND/ELITES: The quake highlighted glaring land ownership issues.

Relocation of survivors into safer, cleaner camps was held up interminably because rich families owned the large tracts of land around Port-au-Prince, while many survivors had no papers to prove ownership of their lots.

Some relocation camps for quake survivors have been seized back by angry landowners and many camp-dwellers have made their way back to the capital regardless as there are no jobs or prospects elsewhere.

A small number of elite families control the bulk of the Haitian economy, making substantial progress difficult.

CHOLERA: As if Haiti's time-old problems weren't enough, the first cholera outbreak in more than a century erupted in mid-October 2010.

The epidemic, blamed on UN peacekeepers from Nepal, shows no sign of abating. A year ago, 3,400 people had died and some 171,300 been infected. By the start of 2012, some 7,000 had died, and over 520,000 been infected.

INFRASTRUCTURE: The capital's roads were gridlocked even before the quake razed thousands of buildings. There is no railway other than a stretch attached to an ex-sugar plantation, and Haiti badly needs more deepwater ports.

In the grip of cholera, a top priority is dealing with the country's lousy sewers. Before the quake, national sanitation coverage -- defined as access to an acceptable latrine -- was just 17 percent. Almost half the population has no access to safe water.

BRAIN DRAIN: Four in five university graduates leave Haiti as soon as they can and every year, hundreds of academics and professionals emigrate in search of a better life. This "brain drain" cripples efforts to foster a thriving middle-class and unless Haiti's best young talent is tempted to stay, efforts to spread the wealth and end the hopeless cycle of poverty will fail.

AGRICULTURE: Aerial photographs of the border Haiti shares with the Dominican Republic show trees and meadows on one side while the other is bare.

Some 97 percent of Haiti's territory is deforested, making it more prone to natural disasters. Soil fertility is so poor that most crops can no longer be supported.

Efforts are under way to boost production but Haitian agriculture is in such a pitiful state that the one-time exporter now has to import rice for 80 percent of its population.

Figures provided by UNICEF, USAID and the CIA Factbook.