Maritime transport costs and port efficiency

Recent literature has emphasized the importance of transport costs and infrastructure in explaining trade, access to markets, and increases in per capita income. For most Latin American countries transport costs are a greater barrier to U.S. markets than import tariffs. The authors investigate the determinants of the costs of shipping to the United States using a large database (more than 300,000 observations a year) on shipments of products at the six-digit level of the Harmonized System of classification from different ports around the world. They find that distance and containerization matter. They find that the efficiency of ports is also important. Improving the efficiency of a port from the 25th to the 75th percentile reduces shipping costs by 12 percent. (On average, having bad ports is equivalent to being 60 percent farther away from markets.) Inefficient ports also increase handling costs, which are part of shipping costs. Finally, the authors try to explain variations in port efficiency. They find that the variations are linked to excessive regulation, the prevalence of organized crime, and the general condition of the country's infrastructure.Environmental Economics&Policies,Common Carriers Industry,Transport and Trade Logistics,Economic Theory&Research,Transport Economics Policy&Planning,Economic Theory&Research,Ports&Waterways,Common Carriers Industry,Environmental Economics&Policies,Transport and Trade Logistics

Port Efficiency, Maritime Transport Costs and Bilateral Trade

Recent literature has emphasized the importance of transport costs and infrastructure in explaining trade, access to markets, and increases in per capita income. For most Latin American countries, transport costs are a greater barrier to U.S. markets than import tariffs. We investigate the determinants of shipping costs to the U.S. with a large database of more than 300,000 observations per year on shipments of products aggregated at six-digit HS level from different ports around the world. Distance volumes and product characteristics matter. In addition, we find that ports efficiency is an important determinant of shipping costs. Improving port efficiency from the 25th to the 75th percentile reduces shipping costs by 12 percent. (Bad ports are equivalent to being 60% farther away from markets for the average country.) Inefficient ports also increase handling costs, which are one of the components of shipping costs. Reductions in country inefficiencies associated to transport costs from the 25th to 75th percentiles imply an increase in bilateral trade of around 25 percent. Finally, we try to explain variations in port efficiency and find that they are linked to excessive regulation, the prevalence of organized crime, and the general condition of the country's infrastructure.

Explaining US Immigration 1971-1998

In this paper we develop and estimate a model to explain the level and source country composition of immigration to the United States since the early 1970s. The model incorporates ratios to the US of source country income and education, and demographic structure, as well as relative inequality as suggested by the Roy model applied to migrant selection. In addition we incorporate the 'friends and relatives effect' as reflected in the stock of previous immigrants and a variety of variables representing different dimensions of the immigration quotas set by policy. We estimate our immigration model on a panel of 81 source countries for the years 1971 to 1998. The results strongly support the influence of economic and demographic variables and geographic characteristics as well as policy variables. We use the results to shed light on the factors that influenced the composition of US immigration by source region. And we provide a further check on its plausibility by simulating the effects of the key changes in immigration policy since the late 1970s.

Where Do U.S. Immigrants Come From, and Why?

The United States has experienced rising immigration levels and changing source since the 1950s. The changes in source have been attributed to the 1965 Amendments to the Immigration Act that abolished country-quotas and replaced them with a system that emphasized family reunification. Some believed that the Amendments would not change the 'traditional' sources of US immigrants. Given this view, it seems all the more remarkable that the sources of immigration changed so dramatically. This paper isolates the economic and demographic fundamentals that determined immigration rates by source from 1971 to 1998 -- income, education, demographic composition and inequality. The paper also allows for persistence - big US foreign-born stocks implying a strong 'friends and neighbors' pull on current immigrant flows. Specific policy variables are included which are derived directly from the quotas allocated to different visa categories. Parameter estimates from the panel data are then used to implement counterfactual simulations that serve to isolate the effects of immigration policy as well as source-country economic and demographic conditions.

What Explains Cross-Border Migration in Latin America?

What accounts for the differences in rates of emigration from Latin America compared with those from other sending regions such as Asia and Africa? Why do cross-border migration rates vary so much across Latin America? What explains those rates? This paper looks at evidence covering the period between the early 1970s and the late 1990s. It represents the start of a project seeking answers to these questions.

Explaining U.S. immigration, 1971-98

The authors develop and estimate a model explaining the level and country-source composition of United States immigration since the early 1970s. The model incorporates ratios of source country income, education, and demographic structure, as well as relative inequality. The authors'model also incorporates both network effects, as reflected in the stock of previous immigrants, and various controls for immigration quota policy. The model is estimated on a panel of 81 source countries for 1971-98. The results strongly support the influence of economic, demographic, and geographic variables as well as policy. The regression results are used to identify those factors that most influenced the changing composition of U.S. immigration by source.Health Monitoring&Evaluation,Public Health Promotion,Voluntary and Involuntary Resettlement,Human Migrations&Resettlements,Gender and Social Development,Health Monitoring&Evaluation,Voluntary and Involuntary Resettlement,Human Migrations&Resettlements,Gender and Social Development,Economic Theory&Research

Effect of a Community Popular Opinion Leader HIV/STI Intervention on Stigma in Urban, Coastal Peru

Evaluating interventions that reduce HIV stigma may help to craft effective stigma-reduction programs. This study evaluates the effects of a community popular opinion leader HIV/STI intervention on stigma in urban, coastal Peru. Mixed effects modeling was used to analyze data on 3,049 participants from the Peru site of the NIHM collaborative trial. Analyses looked at differences between the comparison and intervention groups on a stigma index from baseline to 12- and 24-month follow-up. Sub-analyses were conducted on heterosexual-identified men (esquineros), homosexual-identified men (homosexuales), and socially marginalized women (movidas). Compared to participants in the comparison group, intervention participants reported lower levels of stigma at 12- and 24-month follow-up. Similar results were found within esquineros and homosexuales. No significant differences were found within movidas. Findings suggest that interventions designed to normalize HIV prevention behaviors and HIV communication can reduce HIV-related stigma and change community norms

Multi-omics profiling of mouse gastrulation at single-cell resolution.

Formation of the three primary germ layers during gastrulation is an essential step in the establishment of the vertebrate body plan and is associated with major transcriptional changes1-5. Global epigenetic reprogramming accompanies these changes6-8, but the role of the epigenome in regulating early cell-fate choice remains unresolved, and the coordination between different molecular layers is unclear. Here we describe a single-cell multi-omics map of chromatin accessibility, DNA methylation and RNA expression during the onset of gastrulation in mouse embryos. The initial exit from pluripotency coincides with the establishment of a global repressive epigenetic landscape, followed by the emergence of lineage-specific epigenetic patterns during gastrulation. Notably, cells committed to mesoderm and endoderm undergo widespread coordinated epigenetic rearrangements at enhancer marks, driven by ten-eleven translocation (TET)-mediated demethylation and a concomitant increase of accessibility. By contrast, the methylation and accessibility landscape of ectodermal cells is already established in the early epiblast. Hence, regulatory elements associated with each germ layer are either epigenetically primed or remodelled before cell-fate decisions, providing the molecular framework for a hierarchical emergence of the primary germ layers.CRUK, Wellcome Trust, MRC, BBSRC, EMBL, E

Global Review of the Age Distribution of Rotavirus Disease in Children Aged <5 Years Before the Introduction of Rotavirus Vaccination.

We sought datasets with granular age distributions of rotavirus-positive disease presentations among children <5 years of age, before the introduction of rotavirus vaccines. We identified 117 datasets and fit parametric age distributions to each country dataset and mortality stratum. We calculated the median age and the cumulative proportion of rotavirus gastroenteritis events expected to occur at ages between birth and 5.0 years. The median age of rotavirus-positive hospital admissions was 38 weeks (interquartile range [IQR], 25-58 weeks) in countries with very high child mortality and 65 weeks (IQR, 40-107 weeks) in countries with very low or low child mortality. In countries with very high child mortality, 69% of rotavirus-positive admissions in children <5 years of age were in the first year of life, with 3% by 10 weeks, 8% by 15 weeks, and 27% by 26 weeks. This information is critical for assessing the potential benefits of alternative rotavirus vaccination schedules in different countries and for monitoring program impact