Structural Estimation and Solution of International Trade Models with Heterogeneous Firms

We present an empirical implementation of a general-equilibrium model of international trade with heterogeneous manufacturing firms. The theory underlying our model is consistent with Melitz (2003). A nonlinear structural estimation procedure identifies a set of core parameters and unobserved firm-level trade frictions that best fit the geographic pattern of trade. Once the parameters are identified, we utilize a decomposition technique for computing general-equilibrium counterfactuals. We first assess the economic effects of reductions in measured tariffs. Taking the simple-average welfare change across regions the Melitz structure indicates welfare gains from liberalization that are nearly four times larger than in a standard trade policy simulation. Furthermore, when we compare the economic impact of tariff reductions with reductions in estimated fixed trade costs we find that policy measures affecting the fixed costs are of greater importance than tariff barriers

Structural Estimation and Solution of International Trade Models with Heterogeneous Firms

We present an empirical implementation of a general-equilibrium model of international trade with heterogeneous manufacturing firms. The theory underlying our model is consistent with Melitz (2003). A nonlinear structural estimation procedure identifies a set of core parameters and unobserved firm-level trade frictions that best fit the geographic pattern of trade. Once the parameters are identified, we utilize a decomposition technique for computing general-equilibrium counterfactuals. We illustrate this technique using trade and protection data from the Global Trade Analysis Project (GTAP). We first assess the economic effects of reductions in measured tariffs. Taking the simple-average welfare change across regions the Melitz structure indicates welfare gains from liberalization that are nearly four times larger than in a standard policy simulation model. Furthermore, when we compare the economic impact of tariffs with reductions in estimated fixed trade costs we find that policy measures affecting the fixed costs of firmentry are of greater importance than conventional tariff barriers.

Trade and Welfare: Does Industrial Organization Matter?

Many contemporary theoretic studies of trade over geography reduce to an ex- amination of constant-elasticity reactions to changes in iceberg trade costs. These impacts are readily analyzed in simple constant-returns models based on the Arm- ington (1969) assumption of regionally differentiated goods. Following the line of reasoning suggested by Arkolakis et al. (2008) one can reach the surprising conclu- sion that industrial organization does not matter. In the present paper, we show that this finding is fragile, and with a minor elaboration of their model, the rich industrial-organization features of the popular Melitz (2003) model do, in fact, gen- erate important differences for trade and welfare.Variety effects, Heterogeneous firms, Gains from trade

Evaluation of geotourism potential through geographic information systems

Geotourism aims to provide opportunities for visitors to view and experience geological and geomorphological processes in a way that generates appreciation and understanding of the environment

What to do when you can’t (afford to) collect your own data? : a test case using the longitudinal study of Australian children to investigate the influence of parental context on media use and obesity

The dramatic rise in childhood obesity prevalence in the last two decades has prompted concern about the risk factors that may precipitate or maintain weight gain, or both, in early childhood. Media use has long been implicated in policy debates in Australia, particularly around limits to advertising. However the Australian research funding ecology and dominant paradigms in Australian communication and media studies have resulted in a lack of independent, nationally representative studies upon which to base advice. Australian researchers often can’t afford to collect the kind of data they would like in order to intervene productively as policy actors. As a test case for innovative ways round this dilemma, this paper mobilises secondary data analysis methodologies to explore potential influences of parenting on children’s media use and their weight status.The research reported here uses data from the first three waves of the Longitudinal Study of Australian Children. Results from a path model suggest that children of mothers who were less consistent in the way in which they enforce their rules were more likely to adopt unhealthy lifestyle behaviours, such as sedentary behaviour and consuming unhealthy snacks. Of the lifestyle behaviours considered, time spent watching television or DVDs was the only predictor of child weight status in late childhood. These results suggest a clear pathway linking consistent parenting and other parental practices, children’s lifestyle behaviours and weight status

Observing the spin of a free electron

Long ago, Bohr, Pauli, and Mott argued that it is not, in principle, possible to measure the spin components of a free electron. One can try to use a Stern-Gerlach type of device, but the finite size of the beam results in an uncertainty of the splitting force that is comparable with the gradient force. The result is that no definite spin measurement can be made. Recently there has been a revival of interest in this problem, and we will present our own analysis and quantum-mechanical wave-packet calculations which suggest that a spin measurement is possible for a careful choice of initial conditions

Hidden evidence of non-exponential nuclear decay

The framework to describe natural phenomena at their basics being quantum mechanics, there exist a large number of common global phenomena occurring in different branches of natural sciences. One such global phenomenon is spontaneous quantum decay. However, its long time behaviour is experimentally poorly known. Here we show, that by combining two genuine quantum mechanical results, it is possible to infer on this large time behaviour, directly from data. Specifically, we find evidence for non-exponential behaviour of alpha decay of 8Be at large times from experiments.Comment: 12 pages LaTex, 3 figure