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α: calibrated so average coauthorship-adjusted count equals average raw count
We revisit the natural experiments of division and unification of Germany. The negative shock to local market access following the division of Germany led to a fast and strong downward adjustment of the size of West German cities near the new border. In contrast, the positive shock of reunification did not lead to any change in their relative size. Even three decades after reunification, no convergence can be observed. We show that local subsidies to East Germany could have contributed to this asymmetry in time.