This year's Nobel economics prize has been awarded to Claudia Goldin, an American economic historian, for her work on women's employment and pay.

Prof Goldin's research uncovered key drivers behind the gender pay gap, the Royal Swedish Academy of Sciences said.

She is only the third woman to receive the prize, and the first to not share the award with male colleagues.

The 77-year-old academic currently teaches labour market history at Harvard University in the US.

She had "advanced our understanding of women's labour market outcomes", the Royal Swedish Academy of Sciences said, pointing to her work examining 200 years of data on the US workforce, showing how and why gender differences in earnings and employment rates changed over time.

"This year's Laureate in the Economic Sciences, Claudia Goldin, provided the first comprehensive account of women's earnings and labour market participation through the centuries," the prize-giving body said in a statement.

"Her research reveals the causes of change, as well as the main sources of the remaining gender gap."

Her research found that married women started to work less after the arrival of industrialisation in the 1800s, but their employment picked up again in the 1900s as the service economy grew.

Higher educational levels for women and the contraceptive pill accelerated change, but the gender pay gap remained.

While historically that earnings difference between men and women could be blamed on educational choices made at a young age and career choices, Prof Goldin found that the current earnings gap was now largely due to the impact of having children.

"Claudia Goldin's discoveries have vast societal implications," said Randi Hjalmarsson, a member of the committee awarding the prize.

"She has shown us that the nature of this problem or the source of this underlying gender gap changes throughout history and with the course of development," she said.

Describing her as "a detective", Prof Hjalmarsson said her work had provided a foundation for policymakers in this area around the world.

Globally, about 50% of women participate in the labour market compared to 80% of men, but women earn less and are less likely to reach the top of the career ladder, the prize committee noted.

Prof Goldin was the first woman to receive tenure in Harvard's economics department in 1989. Economics still had an image problem with women, she told the BBC in 2018.

"Even before students enter university they believe economics is a field more oriented to finance and management and women are less interested in those than are men," she said. If we explained economics was about "inequality, health, household behaviour, society, then there'd be a much greater balance," she said.

The economics prize is different to the original prizes in physics, chemistry, physiology or medicine, literature and peace, which were established by Alfred Nobel and first awarded in 1901.

The Sveriges Riksbank Prize in Economic Sciences was established in 1968 and funded by Sweden's central bank.

Elinor Ostrom was the first woman to win the economics prize in 2009, which she was awarded jointly with Oliver E Williamson for research on economic governance.

In 2019 Esther Duflo shared the award with her husband Abhijit Banerjee, and Michael Kremer, for work that focused on poor communities in India and Kenya.