Railroads of the Raj: estimating the impact of transportation infrastructure

How large are the benefits of transportation infrastructure projects, and what explains these benefits? Dave Donaldson investigates the impact of the railway network in colonial India and finds it improved the trading environment and generated considerable welfare gains

Railroads of the Raj: Estimating the Impact of Transportation Infrastructure

How large are the benefits of transportation infrastructure projects, and what explains these benefits? To shed new light on these questions, this paper uses archival data from colonial India to investigate the impact of India's vast railroad network. Guided by four predictions from a general equilibrium trade model, I find that railroads: (1) decreased trade costs and interregional price gaps; (2) increased interregional and international trade; (3) increased real income levels; and (4), that a sufficient statistic for the effect of railroads on welfare in the model (an effect that is purely due to newly exploited gains from trade) accounts for virtually all of the observed reduced-form impact of railroads on real income in the data. I find no spurious effects from over 40,000 km of lines that were approved but - for four different reasons - were never built.

Evolving Comparative Advantage and the Impact of Climate Change in Agricultural Markets: Evidence from 1.7 Million Fields around the World

A large agronomic literature models the implications of climate change for a variety of crops and locations around the world. The goal of the present paper is to quantify the macro-level consequences of these micro-level shocks. Using an extremely rich micro-level dataset that contains information about the productivity—both before and after climate change—of each of 10 crops for each of 1.7 million fields covering the surface of the Earth, we find that the impact of climate change on these agricultural markets would amount to a 0.26% reduction in global GDP when trade and production patterns are allowed to adjust.National Science Foundation (U.S.) (Grant SES-1227635

What Goods Do Countries Trade? A Quantitative Exploration of Ricardo's Ideas

The Ricardian model predicts that countries should produce and export relatively more in industries in which they are relatively more productive. Though one of the most celebrated insights in the theory of international trade, this prediction has received virtually no attention in the empirical literature since the mid-sixties. The main reason behind this lack of popularity is the absence of clear theoretical foundations to guide the empirical analysis. Building on the seminal work of Eaton and Kortum (2002), the present paper offers such foundations and uses them to quantify the importance of Ricardian comparative advantage. Using trade and productivity data from 1997, we estimate that, ceteris paribus, the elasticity of bilateral exports with respect to observed productivity is 6.53. From a welfare standpoint, however, the removal of Ricardian comparative advantage at the industry level would only lead, on average, to a 5.5% decrease in the total gains from trade.

Misallocation in firm production: a nonparametric analysis using procurement lotteries

How costly is the misallocation of production that we might expect to result from distortions such as market power, incomplete contracts, taxes, regulations, or corruption? This paper develops new tools for the study of misallocation that place minimal assumptions on firms’ underlying technologies and behavior. We show how features of the distribution of marginal products can be identified from exogenous variation in firms’ input use, and how these features can be used both to test for misallocation and to quantify the welfare losses that it causes. We then consider an application in which thousands of firms experience demand shocks derived from a lottery-based assignment of public procurement contracts for construction services in Ecuador. Using administrative tax data about these firms, we reject the null of efficiency but estimate that the welfare losses resulting from misallocation are only 1.6% relative to the first-best. Standard parametric assumptions applied to the same setting would suggest losses that are at least an order of magnitude larger

Orbital Maintenance for the Wide Field Infrared Survey Telescope: The Effects of Solar Radiation Pressure and Navigation Accuracies on Station Keeping

The Wide-Field Infrared Survey Telescope (WFIRST), a NASA observatory designed to investigate dark energy and astrophysics, is planned for a launch in 2025 to orbit the Sun-Earth L2 (SEL2) Libration Point. Due to the instability of the SEL2 environment, WFIRST must perform maneuvers to remain in its mission orbit. This paper investigates how different error sources affect the resulting stationkeeping delta v for WFIRST. We study how Solar Radiation Pressure (SRP) modeling affects WFIRST's orbital motion and stability, and how SRP combined with Orbit Determination (OD) errors drive the stationkeeping maneuver magnitudes. Our goal is to determine the best way to model WFIRST's SRP so that we minimize its impact on total stationkeeping delta v required over the mission lifetime

Imports, exports, and earnings inequality: measures of exposure and estimates of incidence

The earnings of individuals depend on the demand for the factor services they supply. International trade may therefore affect earnings inequality because either (i) foreign consumers and firms demand domestic factor services in different proportions than domestic consumers and firms do, an export channel; or (ii) domestic consumers and firms change their demand for domestic factor services in response to the availability of foreign goods, an import channel. Building on this idea, we develop new measures of export and import exposure at the individual level and provide estimates of their incidence across the earnings distribution. The key input fed into our empirical analysis is a unique administrative data set from Ecuador that merges firm-to-firm transaction data, employer-employee matched data, owner-firm matched data, and firm-level customs transaction records. We find that export exposure is pro-middle class, import exposure is pro-rich, and in terms of overall incidence, the import channel is the dominant force. As a result, earnings inequality in Ecuador is higher than it would be in the absence of trade

Working against the clock: A model for rural STEMI triage

Residents in rural communities have higher incident of cardiac death and risk factors associated with cardiac disease. Living in a rural region can add precious time that amplifies cardiac death during a ST-elevated myocardial infarction (STEMI) episode. The consensus is that improved efficiencies can increase myocardial salvage and decrease STEMI mortality rates. This article identifies issues that may impact pre-hospital STEMI triage of patients in a rural region of the United States (U.S.). A qualitative research design was chosen to gain insight into emergency personnel perceptions of pre-hospital STEMI triage. The participants (n=18) were obtained from a convenience sample in rural Northeast Texas, U.S. Data were gathered by individual and group semi-structured interviews. Themes were identified, synthesized, and oriented to offer a basis for understanding opportunities to improve the delivery of rural STEMI care. This study demonstrated that quality improvement initiatives aimed at achieving pre-hospital STEMI triage efficiencies have dependencies on teamwork, technology, and training in the context of three stages a) pre-transport, b) door-to-door, and c) post-transport. A pre-hospital STEMI triage model is considered. By incorporating this model, emergency medical coordinators in rural communities have a better opportunity to facilitate timely reperfusion therapy for this high risk populous

New Trade Models, Same Old Gains?

Micro-level data have had a profound influence on research in international trade over the last ten years. In many regards, this research agenda has been very successful. New stylized facts have been uncovered and new trade models have been developed to explain these facts. In this paper we investigate to what extent answers to new micro-level questions have affected answers to an old and central question in the field: how large are the welfare gains from trade? A crude summary of our results is: "So far, not much." (JEL F11, F12)

Significant transcriptional changes in 15q duplication but not Angelman syndrome deletion stem cell-derived neurons

Abstract Background The inability to analyze gene expression in living neurons from Angelman (AS) and Duplication 15q (Dup15q) syndrome subjects has limited our understanding of these disorders at the molecular level. Method Here, we use dental pulp stem cells (DPSC) from AS deletion, 15q Duplication, and neurotypical control subjects for whole transcriptome analysis. We identified 20 genes unique to AS neurons, 120 genes unique to 15q duplication, and 3 shared transcripts that were differentially expressed in DPSC neurons vs controls. Results Copy number correlated with gene expression for most genes across the 15q11.2-q13.1 critical region. Two thirds of the genes differentially expressed in 15q duplication neurons were downregulated compared to controls including several transcription factors, while in AS differential expression was restricted primarily to the 15q region. Here, we show significant downregulation of the transcription factors FOXO1 and HAND2 in neurons from 15q duplication, but not AS deletion subjects suggesting that disruptions in transcriptional regulation may be a driving factor in the autism phenotype in Dup15q syndrome. Downstream analysis revealed downregulation of the ASD associated genes EHPB2 and RORA, both genes with FOXO1 binding sites. Genes upregulated in either Dup15q cortex or idiopathic ASD cortex both overlapped significantly with the most upregulated genes in Dup15q DPSC-derived neurons. Conclusions Finding a significant increase in both HERC2 and UBE3A in Dup15q neurons and significant decrease in these two genes in AS deletion neurons may explain differences between AS deletion class and UBE3A specific classes of AS mutation where HERC2 is expressed at normal levels. Also, we identified an enrichment for FOXO1-regulated transcripts in Dup15q neurons including ASD-associated genes EHPB2 and RORA indicating a possible connection between this syndromic form of ASD and idiopathic cases.https://deepblue.lib.umich.edu/bitstream/2027.42/140784/1/13229_2018_Article_191.pd