Amartya Sen's ideas constitute the core principles of a development approach that has evolved in the Human Development Reports. This approach is a "paradigm" based on the concept of well-being that can help define public policy, but does not embody a set of prescriptions. The current movement from an age of development planning to an age of globalization has meant an increasing attention to agency aspects of development. While earlier Human Development Reports emphasized measures such as the provision of public services, recent ones have focused more on people's political empowerment. This paper reflects on Sen's work in light of this shift in emphasis. Gender analysis has been central to the development of the new agency-driven paradigm, and gender equity is a core concern. A gender perspective has also helped highlight important aspects of this paradigm, such as the role of collective agency in promoting development.