The authors use different data sets to investigate the dependence of transport costs on geography and infrastructure. Infrastructure is an important determinant of transport costs, especially for landlocked countries. Analysis of bilateral trade data confirms the importance of infrastructure and gives an estimate of the elasticity of trade flows with respect to the trade cost factor of around-3. A deterioration of infrastructure from the median to the 75th percentile raises transport costs by 12 percentage points and reduces trade volumes by 28 percent. Analysis of African trade flows indicates that their relatively low level is largely due to poor infrastructure.

No abstract

We find that prior to World Trade Organization membership, countries set import tariffs 9 percentage points higher on inelastically supplied imports relative to those supplied elastically. The magnitude of this effect is similar to the size of average tariffs in these countries, and market power explains more of the tariff variation than a commonly used political economy variable. Moreover, US trade restrictions not covered by the WTO are significantly higher on goods where the United States has more market power. We find strong evidence that these importers have market power and use it in setting noncooperative trade policy. (JEL F12, F13)

Using a dynamic, heterogeneous firms model with sunk costs of exporting we show that: (i) investment and entry into export markets is reduced when trade policy is uncertain and (ii) credible preferential trade agreements (PTAs) increase trade even if applied trade barriers are currently low. We structurally estimate the effect of policy uncertainty on firm entry following Portugal's accession to the European Community in 1986 and find that (i) the trade policy reform accounted for a large fraction of the observed Portuguese exporting firms' entry and sales (ii) the accession removed uncertainty about future EC trade policies and (iii) this uncertainty channel accounted for a large fraction of the predicted growth. These results have broader implications for other PTAs and our approach can be applied to analyze other sources of policy uncertainty.JEL classification: D8, D92, E22, F02, F1, F5, H32, O24.

Most countries are members of preferential trade agreements (PTAs). The effect of these agreements has attracted much interest and raised the question of whether PTAs promote or slow multilateral trade liberalization, i.e., whether they are a "building block" or "stumbling block" to multilateral liberalization. Despite this long-standing concern with PTAs and the lack of theoretical consensus, there is no systematic evidence on whether they are actually a stumbling block to multilateral liberalization. We use detailed data on U.S. multilateral tariffs to provide the first systematic evidence that the direct effect of PTAs was to generate a stumbling block to its MTL. We also provide evidence of reciprocity in multilateral tariff reductions. (JEL: D78; F13; F14; F15)