According to the page "Economists facing the crisis" in Spain women charge almost € 5000 less per year than men, so when it comes to retirement, women receive almost 60% less pay. Although women are equal or even more educated than men in many jobs, they are not equally valued and that slows down their professional advances.
Still the gender gap in earnings isn't equal. However, in the US, since the "Equal Pay" Act of 1963 signed by President John F. Kennedy, it is illegal to pay men and women different salaries for the same work. Law that has also been applied by some European countries such as France, Germany and Poland. And although in Spain Article 35 of the Constitution and Article 28 of the Workers' Statute says: "equal remuneration by *censured*". But although there is this law, it does not apply, and women earn 20% less than men. If the current trend of improvement continues, it is foreseen that this gender gap will close in 170 years!