Many manufacturing industries, including the computer industry, have seen large increases in productivity growth rates and have experienced a reduction in average establishment size and a decrease in the variance of the sizes of plants. A vintage capital model is introduced where learning increases productivity on any given technology and firms choose when to adopt a new vintage. In the model, ...

Soon, the Large Hadron Collider at CERN will advance the experimental frontier of particle physics to the heart of the Fermi scale, reaching energies around one trillion electron volts for collisions among the basic constituents of matter. We do not know what the new wave of exploration will find, but the discoveries we make and the new puzzles we encounter are certain to change the face of par...