By Laura D'Andrea Tyson
Like most Americans, I have been deeply moved by recent images of Afghan citizens celebrating the return of freedom to war-ravaged Kabul--images of people listening to music for the first time in years, of women with uncovered faces walking alone, and of children playing. Such images remind us that human well-being depends on freedom of choice and simple things. Human development, as Nobel laureate Amartya Sen has counseled, is a process of expanding the real freedoms that people enjoy. Successful development requires the removal of major societal sources of "unfreedom" including political tyranny and intolerance. But it also requires the eradication of crushing poverty.