With an average annual growth rate of 5.5%, some of the highest salaries in the region and low unemployment figures, Chile is seen as a role model for developing countries by Western economists.

So why would many Chileans tell pollsters that they are planning to vote for someone who advocates radical change rather than continuity in the presidential election on 17 November?

The answer may partly lie in the mass student protests of 2011.

The protests, the largest since the regime of Gen Augusto Pinochet came to an end in 1990, showed that behind Chile's economic success lay an increasingly frustrated society.

Chile has the most expensive higher education system in Latin America, with students and their parents struggling to pay university fees running into the tens of thousands of dollars.

According to Pamela Figueroa, director of the School of Politics at Chile's Central University, the protests have shown that a reform of the education system is crucial to fighting Chile's inequality.

"It's the biggest challenge for the next president," she says.

The disparity between Chile's top earners and the country's poorest is bigger than in any other member nation of the Organisation for Economic Co-operation and Development.

Figures show that the average income of the wealthiest 10% is 27 times higher than that of the poorest 10%.

And every day more Chileans are speaking out against this disparity.

"Chileans know their civil and economic rights now, and they know they are empowered to change things they are not satisfied with," Ms Figueroa explains.

Discontent

Public protests, from students, environmentalists, indigenous, and gay rights groups, have become more and more frequent in a way not seen in Chile since the 1990s.

So how do the two main candidates in Sunday's election plan to fulfil the expectations of this empowered middle class and of a vocal student movement?

"We need an education reform, social programmes and a labour agenda that fights the big gap between those who have bigger salaries and those who have lower ones," Michelle Bachelet of the centre-left New Majority coalition told the BBC.

Ms Bachelet, who already served one term as president from 2006 to 2010, said it was time Chile entered "a new era".

She advocates a radical overhaul of Chile's fiscal policy, raising corporate dues while lowering personal income taxes.

She argues this would help fight inequality and, at the same time, fund an ambitious free public education system.

Her programme is popular with low-income and middle-class families.

Front runner

Recent polls suggest the 62-year-old paediatrician is the favourite in Sunday's election with 47% of those polled saying they would vote for her.

According to that same poll, her main rivals could trail well behind, with just 15% of those surveyed saying they would vote for candidates other than Ms Bachelet.

Ms Bachelet's main rival is 60-year-old former labour minister Evelyn Matthei, from the party of current President Sebastian Pinera, who is barred by the constitution from running again

Ms Matthei came to the campaign rather late, only being chosen as the candidate for the right after two other candidates dropped out.

Polls suggest the daughter of a former air force general may struggle to make it into the second round, but Ms Matthei says she is determined to put up a good fight.

She has warned that Ms Bachelet's plans for a fee-free public education system would blow a hole in the country's budget.

Ms Matthei advocates a "competitive education system" in which poor families can get public funding to enrol their children in school and those teachers with the best results receive subsidies.

She also favours lowering taxes for businesses, and promises to create more employment opportunities as a way of boosting equality.

Scepticism

If there is something Ms Bachelet, Ms Matthei and the remaining seven presidential candidates agree on, it is the need to reform Chile's constitution.

"Chile is now a consolidated democracy, but its institutions go back to the years of Augusto Pinochet's military regime," political analyst Pamela Figueroa explains.

"There is a growing concern that the current institutions don't take into account that Chile now has a more diverse population with more social and economic rights than it used to have 30 years ago," she adds.

Most of the candidates, including Michelle Bachelet, are pushing for a totally new constitution, while Ms Matthei favours minor reforms to the current text.

What all candidates have been facing during the campaign is a strong dose of scepticism towards Chile's political class.

And, as a former president, Ms Bachelet in particular had to confront those who felt let down by her during her first term in office.

In La Pintada, a poor neighbourhood of the capital Santiago, one student is willing to give her one more chance.

"I agree we need a fair distribution of wealth, we need better education, but she lied to us once," he says referring to Ms Bachelet's failure to get education reform passed in Congress during her last term as president.

"I hope she keeps her promises this time!"