Island Matching

A synthesis of the Lucas-Prescott island model and the Mortensen- Pissarides matching model of unemployment is studied. By assumption, all unmatched workers and jobs are randomly assigned to islands at the beginning of each period and the number of matches that form on a particular island is the minimum of the two realizations. When calibrated to the recently observed averages of U.S. unemployment and vacancy rates, the model fits the observed vacancy-unemployment Beveridge relationship very well and implies an implicit log linear relationship between the job finding rate and the vacancy-unemployment relationship with an elasticity near 0.5. The constrained efficient solution to the model is decentralized by a equilibrium outcome in which wages on each island are determined by a modified auction. Although the efficient solution explains only about 25% of the observed volatility in the U.S. vacancy-unemployment ratio, an equilibrium outcome in which wages are determined as the solution to a strategic bargaining game explains almost all of it.

Polynesian settlement of New Zealand and the impacts of volcanism on early Maori society: An update

Presents an overview of the timing of Polynesian settlement in New Zealand, discussing the application of tephrochronology and rat and avian bone dating to the problem. The impacts of volcanism on early Maori society are examined, including the catastrophic impacts of the Tarawera eruption of 1886

Two-fluid magnetic island dynamics in slab geometry: II - Islands interacting with resistive walls or static external resonant magnetic perturbations

The dynamics of a propagating magnetic island interacting with a resistive wall or a static external magnetic perturbation is investigated using two-fluid, drift-MHD theory in slab geometry. In both cases, the island equation of motion is found to take exactly the same form as that predicted by single-fluid MHD theory. Three separate ion polarization terms are found in the Rutherford island width evolution equation. The first is the drift-MHD polarization term for an isolated island, and is completely unaffected by interaction with a wall or magnetic perturbation. Next, there is the polarization term due to interaction with a wall or magnetic perturbation which is predicted by single-fluid MHD theory. Finally, there is a hybrid of the other two polarization terms. The sign of this term depends on many factors. However, under normal conditions, it is stabilizing if the unperturbed island propagates in the ion diamagnetic direction (in the lab. frame), and destabilizing if it propagates in the electron diamagnetic direction

Effect of oil palm sustainability certification on deforestation and fire in Indonesia.

Many major corporations and countries have made commitments to purchase or produce only "sustainable" palm oil, a commodity responsible for substantial tropical forest loss. Sustainability certification is the tool most used to fulfill these procurement policies, and around 20% of global palm oil production was certified by the Roundtable on Sustainable Palm Oil (RSPO) in 2017. However, the effect of certification on deforestation in oil palm plantations remains unclear. Here, we use a comprehensive dataset of RSPO-certified and noncertified oil palm plantations (∼188,000 km2) in Indonesia, the leading producer of palm oil, as well as annual remotely sensed metrics of tree cover loss and fire occurrence, to evaluate the impact of certification on deforestation and fire from 2001 to 2015. While forest loss and fire continued after RSPO certification, certified palm oil was associated with reduced deforestation. Certification lowered deforestation by 33% from a counterfactual of 9.8 to 6.6% y-1 Nevertheless, most plantations contained little residual forest when they received certification. As a result, by 2015, certified areas held less than 1% of forests remaining within Indonesian oil palm plantations. Moreover, certification had no causal impact on forest loss in peatlands or active fire detection rates. Broader adoption of certification in forested regions, strict requirements to avoid all peat, and routine monitoring of clearly defined forest cover loss in certified and RSPO member-held plantations appear necessary if the RSPO is to yield conservation and climate benefits from reductions in tropical deforestation

Matching and Saving in Continuous Time: Theory

We analyse optimal saving of risk-averse households when labour income stochastically jumps between two states. The generalized Keynes-Ramsey rule includes a precautionary savings term. A phase diagram analysis illustrates consumption and wealth dynamics within and between states. There is an endogenous lower and upper limit for wealth. We derive the Fokker-Planck equations for the densities of individual wealth and employment status. These equations also characterize the aggregate distribution of wealth and allow us to describe general equilibrium. An optimal consumption path exists and distributions converge to a unique limiting distribution.matching model, optimal saving, incomplete markets, Poisson uncertainty, Fokker-Planck equations, general equilibrium

Analysis of the evolution of the Spanish labour market through unsupervised learning

Unemployment in Spain is one of the biggest concerns of its inhabitants. Its unemployment rate is the second highest in the European Union, and in the second quarter of 2018 there is a 15.2% unemployment rate, some 3.4 million unemployed. Construction is one of the activity sectors that have suffered the most from the economic crisis. In addition, the economic crisis affected in different ways to the labour market in terms of occupation level or location. The aim of this paper is to discover how the labour market is organised taking into account the jobs that workers get during two periods: 2011-2013, which corresponds to the economic crisis period, and 2014-2016, which was a period of economic recovery. The data used are official records of the Spanish administration corresponding to 1.9 and 2.4 million job placements, respectively. The labour market was analysed by applying unsupervised machine learning techniques to obtain a clear and structured information on the employment generation process and the underlying labour mobility. We have applied two clustering methods with two different technologies, and the results indicate that there were some movements in the Spanish labour market which have changed the physiognomy of some of the jobs. The analysis reveals the changes in the labour market: the crisis forces greater geographical mobility and favours the subsequent emergence of new job sources. Nevertheless, there still exist some clusters that remain stable despite the crisis. We may conclude that we have achieved a characterisation of some important groups of workers in Spain. The methodology used, being supported by Big Data techniques, would serve to analyse any alternative job market.Ministerio de Economía y Competitividad TIN2014-55894-C2-R y TIN2017-88209-C2-2-R, CO2017-8678

Environmental factors influence the rate of human herpesvirus type 8 infection in a population with high incidence of classic Kaposi sarcoma

High prevalence of human herpesvirus type 8 (HHV-8) infection has been reported on the island of Sardinia. Among emigrants from Sardinia, rates of HHV-8 infection are lower than they are in Sardinia and are similar to those observed in the local population. Thus, environmental factors seem to play a relevant role in affecting the prevalence of HHV-8 infection

Unemployment and endogenous reallocation over the business cycle

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Rupture Along 400 km of the Bering Fracture Zone in the Komandorsky Islands Earthquake (M_W 7.8) of 17 July 2017

The 17 July 2017 Komandorsky Islands M_W 7.8 earthquake involved arc-parallel right-lateral patchy strike-slip faulting along ~400 km of the Bering Fracture Zone (BFZ) in the westernmost Aleutian Islands back arc. The large size of the earthquake indicates that the BFZ serves regionally as the primary plate boundary extending from the Near Islands to Kamchatka, with the fore-arc Komandorsky Sliver translating rapidly parallel to the Aleutian Trench. The slip distribution is determined by analysis of seismic, tsunami, and geodetic observations. Fault displacements of 4 to 8.5 m, mostly in the upper 15 km, but with localized extension to 20 to 30 km depth along a ~100 km long segment of the BFZ, are comparable to the possible slip deficit since the last major earthquakes in this region in 1849 and 1858, given an estimated 5.1 cm/yr rate between the Komandorsky Sliver and the Bering Plate