More than 100 natural disasters strike the United States every year, causing extensive fatalities and damages. We construct the universe of US federally designated natural disasters from 1920 to ...2010. We find that severe disasters increase out-migration rates at the county level by 1.5 percentage points and lower housing prices/rents by 2.5–5.0 percent. The migration response to milder disasters is smaller but has been increasing over time. The economic response to disasters is most consistent with falling local productivity and labor demand. Disasters that convey more information about future disaster risk increase the pace of out-migration.
Areas differ in their propensity to experience natural disasters. Exposure to disaster risks can be reduced either through migration (i.e., self-protection) or through public infrastructure ...investment (e.g., building seawalls). Using migration data from the 1920s and 1930s, this paper studies how the population responded to disaster shocks in an era of minimal public investment. We find that, on net, young men move away from areas hit by tornados but are attracted to areas experiencing floods. Early efforts to protect against future flooding, especially during the New Deal era of the late 1930s, may have counteracted an individual migration response. PUBLICATION ABSTRACT
Right on time for several large-scale experimental upgrades, the widely used and long-standing air shower simulation toolkit CORSIKA 7 will be updated to a "state of the art" C++ simulation ...framework. To meet the simultaneously rising demand for high-quality air shower simulations and the ecologic necessity to reduce energy consumption several new possibilities for optimizations will be tested. One of the biggest runtime consumers in the classic simulation is the propagation of fluorescence and Cherenkov photons through the atmosphere. With the rising popularity of highly parallel computing architectures, the runtime of this specific workload can be reduced significantly. In this Work, the most common architecture, in the form of GPUs, is utilized for this task. Two competing implementations in Cuda and OpenCL are compared and different techniques presented that enable a high GPU utilization.
Recovery from the Great Depression Hausman, Joshua K.; Rhode, Paul W.; Wieland, Johannes F.
The American economic review,
02/2019, Letnik:
109, Številka:
2
Journal Article
Recenzirano
Odprti dostop
From March to July 1933, US industrial production rose 57 percent. We show that an important source of recovery was the effect of dollar devaluation on farm prices, incomes, and consumption. ...Devaluation immediately raised traded crop prices, and auto sales grew more rapidly in states and counties most exposed to these price increases. The response was amplified in counties with more severe farm debt burdens. For plausible assumptions about farmers’ relative MPC, the incidence of higher farm prices, and the aggregate multiplier, this redistribution to farmers accounted for a substantial portion of spring 1933 growth. This farm channel thus provides an example of how the distributional consequences of macroeconomic policies can have large aggregate effects. That recovery in 1933 benefited from redistribution to farmers suggests an important limitation to the use of 1933 as a guide to the effects of monetary regime changes in other circumstances.
We describe our digitization of a uniquely detailed study of 19
century production methods assembled by the United States Department of Labor (1899). The staff spent five years collecting and ...assembling data on the production of hundreds of highly specific products (as well as some services) at the production operations level using traditional artisanal (“hand”) methods and by the (then) most modern “machine” methods, measuring productivity in terms of the time taken to complete a specific task or set of tasks. The data proved too complex and voluminous to use, except as a source of anecdotes, until now. We describe how we have made these invaluable data from the first industrial revolution tractable to modern analysis and how they might be used to provide insight and perspective into the effects of robotics and artificial intelligence on labor during the third industrial revolution.
The Intergovernmental Panel on Climate Change projects that temperatures in the major grain-growing areas of North America will rise by 3–4 °C by 2100. Such abrupt changes will create major ...challenges, significantly altering the area suitable for wheat. The historical record offers insight into the capability of agriculture to adapt to climatic challenges. Using a new county-level dataset on wheat production and climate norms, we show that during the 19th and 20th centuries North American grain farmers pushed wheat production into environments once considered too arid, too variable, and too harsh to cultivate. As summary measures, the median annual precipitation norm of the 2007 distribution of North American wheat production was one-half that of the 1839 distribution, and the median annual temperature norm was 3.7 °C lower. This shift, which occurred mostly before 1929, required new biological technologies. The Green Revolution associated with the pioneering work of Norman Borlaug represented an important advance in this longer process of biological innovation. However, well before the Green Revolution, generations of North American farmers overcame significant climatic challenges.
High-energy muons can travel large thicknesses of matter. For underground neutrino and cosmic ray detectors the energy loss of muons has to be known accurately for simulations. In this article the ...next-to-leading order correction to the average energy loss of muons through bremsstrahlung is calculated using a modified Weizsäcker–Williams method. An analytical parametrisation of the numerical results is given.
Context.
The origin of the
γ
-ray emission of the blazar
Mrk 421
is still a matter of debate.
Aims.
We used 5.5 years of unbiased observing campaign data, obtained using the FACT telescope and the
...Fermi
-LAT detector at TeV and GeV energies, the longest and densest so far, together with contemporaneous multi-wavelength observations, to characterise the variability of
Mrk 421
and to constrain the underlying physical mechanisms.
Methods.
We studied and correlated light curves obtained by ten different instruments and found two significant results.
Results.
The TeV and X-ray light curves are very well correlated with a lag of < 0.6 days. The GeV and radio (15 Ghz band) light curves are widely and strongly correlated. Variations of the GeV light curve lead those in the radio.
Conclusions.
Lepto-hadronic and purely hadronic models in the frame of shock acceleration predict proton acceleration or cooling timescales that are ruled out by the short variability timescales and delays observed in Mrk 421. Instead the observations match the predictions of leptonic models.
PROPOSAL is a Monte Carlo simulation library, usable both in C++ and via a python wrapper, used to describe the propagation of highly energetic particles. Originally designed to provide a precise ...description of muon and tau propagation, recent updates introduced both photon propagation as well as a more precise implementation of electron and positron propagation. Due to its modular code structure, the user can either use the complete propagation routine provided by PROPOSAL to easily simulate all secondaries created during particle propagation or extract individual parts of the propagation routine to use them in specific applications. Examples of applications of PROPOSAL are its usage in the simulation chain of the IceCube Neutrino Observatory as well as its implementation as an electromagnetic shower model in the upcoming eighth version of the extensive air shower simulation framework CORSIKA. This talk provides a general overview of the functionalities and possibilities of PROPOSAL.
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