Big companies keep pulling ahead. Smaller ones watch their lead shrink. Artificial intelligence isn’t leveling the field. It’s doing the opposite. History offers a clear pattern. Corporate concentration in the US has climbed since the 1930s. It rises faster during periods of rapid technological change. Goldman Sachs chief economist Jan Hatzius and his team laid this out in a recent analysis. “Corporate concentration in the US has steadily climbed since the 1930s, rising more rapidly during periods of faster technological change,” they wrote. ( Yahoo Finance ) The mechanism feels familiar. New technologies carry high fixed deployment costs. Marginal costs of scaling stay low. Firms with capital and organizational muscle spread those costs across bigger output. They grab market share from rivals.…