6)  Eventually, global supply reached bottlenecks in the form of commodity supply constraints, US monetary policy was gradually tightened, and house prices peaked. At that point, the large risk exposures that had accumulated in the financial system suddenly became apparent, precipitating the turmoil.
19 Against this background, a key avenue to improve efficiency and profitability is bank consolidation. Indeed, some of the factors of change are having an impact on scale economies and the optimal bank size. Setting up the technological infrastructure needed to do banking business today requires conspicuous investment; in the face of negligible marginal costs, this is a factor increasing scale economies.