India may need to sustain annual growth of more than 9% to achieve its developed-economy ambition by 2047. Economists say reaching that goal will require stronger manufacturing, private and foreign investment, exports, domestic savings and job creation, while avoiding the middle-income trap.

Modi's vision for a developed India faces challenges as current growth rates fall short of ambitious economic targets.

India may need to sustain annual growth of more than 9% to achieve its developed-economy ambition by 2047. Economists say reaching that goal will require stronger manufacturing,…