Several academics and practitioners have pointed out that inflation follows a seemingly exogenous statistical process, unrelated to the output gap, leading some to argue that the Phillips curve has weakened or disappeared. In this paper we explain why this seemingly exogenous process arises, or,...

Helpman, Melitz, and Rubinstein (2008)HMRpresent a rich theoretical model to study the determinants of bilateral trade flows across countries. The model is then empirically implemented through a two-stage estimation procedure. This note seeks to clarify some econometric aspects of the estimation...

We extend the simulation results given in Santos Silva and Tenreyro (2006, The log of gravity,ʺ The Review of Economics and Statistics, 88, 641-658) by considering data generated as a finite mixture of gamma variates. Data generated in this way can naturally have a large proportion of zeros and...

Every year during the second and thirdquarters (the hot seasonʺ) housing markets in the UK and the US experience systematic above-trend increases in both prices and transactions. During the fourth and first quarters (the cold seasonʺ), house prices and transactions fall below trend. We propose...

We note that the existence of the maximum likelihood estimates for Poisson regression depends on the data configuration. Because standard software does not check for this problem, the practitioner may be surprised to find that in some applications estimation of the Poisson regression is...

We extend the simulation results given in Santos-Silva and Tenreyro (2006, "The Log of Gravity", The Review of Economics and Statistics, 88, pp.641-658) by considering data generated as a finite mixture of gamma variates. Data generated in this way can naturally have a large proportion of zeros...