Final answer:
The increase in female employment was spurred by various factors, including international conflicts and societal shifts towards women's rights and changing roles in the workforce.
Step-by-step explanation:
The increase in female employment was spurred by various factors, including social and demographic changes. One of the main reasons was the impact of international conflicts, such as World War I and World War II, which created a surge in employment opportunities for women. Additionally, societal shifts towards women's rights and the changing roles of women in the workforce also played a significant role in increasing female employment.