France, Oct. 3 -- Germany marks 35 years since its reunification on Friday, but the country's East-West divide continues to shape its economy and its political landscape.

The anniversary celebrates the political turning point of 1990, when East and West Germany became one nation after more than four decades of division.

Integration was swift, dramatic and expensive. Some estimates put the cumulative cost of reunification at more than €2 trillion between 1990 and the mid-2010s.

In the years following reunification, the federal government poured money into infrastructure, social welfare and retraining programmes in the former East. Public and private transfers to that half of the country have remained substantial, sometimes reachin...