Education promotes growth, and might also independently promote political pluralization by reducing the costs of political action in support of relatively democratic regimes. Schooling makes democratic revolutions against dictatorships more probable and successful antidemocratic coups less probable. After analyzing more than a hundred countries, Robert J. Barro found that higher incomes and higher levels of (primary) education predict higher freedoms. He also found significant time lags between the appearance of a factor positive for electoral rights and its expression in politics. He interpreted such lags as tokens of inertia in institutions affected by changes in economic and social variables, and noted that after about two decades “the level of democracy is nearly fully determined by the economic and social variables”. This observation helps one to understand why a rapidly growing country such as China has a freedom rating today well below the level that its current income would predict.