Franco Nardini

Endogenous innovation waves and economic growth

We propose a simple model where large innovation waves arise from the endogenous propagation of information around sectors. Innovators of each sector invest in internal R&D and in local search for information. We show that depending on the structural parameters of the single sectors, some of the R&D sectors will engage in local search while others will not. Through localised search for information, technology adopted in certain sectors can be adopted also in other sectors, leading to a large technological correlation, and eventually to long ranged innovation waves. We characterise the endogenous balanced growth path of the economy, and the short run fluctuations around it. The model predicts a linear, positive relationship between the short run fluctuations and the long run growth rate. We test this latter relationship and find that we cannot reject the predictions of the model.

Exponential decay for the eigenfunctions of the two body relativistic hamiltonian

AbstractAn exponential decay result for the solutionsu of the equation

The Emergence of Paradigm Setters through Firms' Interaction and Network Formation

(\sqrt {1 - \Delta } + V)u = f

The Dynamical System

is proved under the hypotheses thatV converges to zero at infinity andf decays exponentially. This ensures that the eigenfunctions of the two body relativistic spinless Hamiltonian

Firms Interaction and Technological Paradigms

\sqrt {1 - \Delta } + V

Approximation of Schrödinger eigenvalues and eigenfunctions by canonical perturbation theory: The periodically driven quantum rotator

decay exponentially: this result parallels the well-known one valid in the non-relativistic case.