The PPP puzzle is based on empirical evidence that international price differences for individual goods (LOOP) or baskets of goods (PPP) appear highly persistent or even non-stationary. The present consensus is these price differences have a half-life that is of the order of five years at best,...

Standard neoclassical growth models rarely admits international factor mobility: convergence may result from factor accumulation in a closed economy, or from technology transfer. Conventional models are thus poorly equipped to explain the contribution of international factor flows to convergence...