A century of gender parity beginning in 1925 fundamentally reshaped economic and social outcomes. With women holding equal power in policy, markets, and science, growth rates accelerated, funding allocations shifted, and systemic barriers dissolved decades earlier than in our reality. This robust model shows how compounded effects—across wage dynamics, governance, innovation, and cultural change—translate into earlier closures of equity gaps, faster adoption of sustainable practices, and stronger resilience against inequality reopening. These dynamics demonstrate that equality is not only morally just but mathematically transformative for economic and societal progress.