Ethnic enclaves and immigrant labour market outcomes: quasi-experimental evidence

This study investigates empirically how residence in ethnic enclaves affects labour market outcomes of refugees. Self-selection into ethnic enclaves in terms of unobservable characteristics is taken into account by exploitation of a Danish spatial dispersal policy which randomly disperses new refugees across locations conditional on six individual-specific characteristics. The results show that refugees with unfavourable unobserved characteristics are found to self-select into ethnic enclaves. Furthermore, taking account of negative self-selection, a relative standard deviation increase in ethnic group size on average increases the employment probability of refugees by 4 percentage points and earnings by 21 percent. I argue that in case of heterogenous treatment effects, the estimated effects are local average treatment effects

The construction of neighbourhoods and its relevance for the measurement of social and ethnic segregation: evidence from Denmark

In this paper we propose a model for constructing neighbourhoods based on georeferenced data and administrative data. The 431,233 inhabited hectare cells in Denmark are clustered into 9,404 small and 2,296 large neighbourhoods, inhabited on average in 2004 by 572 and 2,343 persons respectively. The priorities in the clustering process are to obtain neighbourhoods that are unaltered over time, delineated by physical barriers, compact, homogeneous in terms of type of housing and ownership, relatively small, homogeneous in terms of number of inhabitants, and comprised of a contiguous cluster of cells. To illustrate the importance of detailed neighbourhood information we compare social and ethnic segregation measured by Isolation and Dissimilation indices on the levels of municipalities and of small neighbourhoods. Our findings demonstrate substantial variation in the residential mix in neighbourhoods within a given municipality, and thus show the importance of having information on a more detailed geographical level than that of the municipality

Dynamic Package Interfaces - Extended Version

A hallmark of object-oriented programming is the ability to perform computation through a set of interacting objects. A common manifestation of this style is the notion of a package, which groups a set of commonly used classes together. A challenge in using a package is to ensure that a client follows the implicit protocol of the package when calling its methods. Violations of the protocol can cause a runtime error or latent invariant violations. These protocols can extend across different, potentially unboundedly many, objects, and are specified informally in the documentation. As a result, ensuring that a client does not violate the protocol is hard. We introduce dynamic package interfaces (DPI), a formalism to explicitly capture the protocol of a package. The DPI of a package is a finite set of rules that together specify how any set of interacting objects of the package can evolve through method calls and under what conditions an error can happen. We have developed a dynamic tool that automatically computes an approximation of the DPI of a package, given a set of abstraction predicates. A key property of DPI is that the unbounded number of configurations of objects of a package are summarized finitely in an abstract domain. This uses the observation that many packages behave monotonically: the semantics of a method call over a configuration does not essentially change if more objects are added to the configuration. We have exploited monotonicity and have devised heuristics to obtain succinct yet general DPIs. We have used our tool to compute DPIs for several commonly used Java packages with complex protocols, such as JDBC, HashSet, and ArrayList.Comment: The only changes compared to v1 are improvements to the Abstract and Introductio

Potential of the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor for the monitoring of terrestrial chlorophyll fluorescence

Global monitoring of sun-induced chlorophyll fluorescence (SIF) is improving our knowledge about the photosynthetic functioning of terrestrial ecosystems. The feasibility of SIF retrievals from spaceborne atmospheric spectrometers has been demonstrated by a number of studies in the last years. In this work, we investigate the potential of the upcoming TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor satellite mission for SIF retrieval. TROPOMI will sample the 675–775 nm spectral window with a spectral resolution of 0.5 nm and a pixel size of 7 km × 7 km. We use an extensive set of simulated TROPOMI data in order to assess the uncertainty of single SIF retrievals and subsequent spatio-temporal composites. Our results illustrate the enormous improvement in SIF monitoring achievable with TROPOMI with respect to comparable spectrometers currently in-flight, such as the Global Ozone Monitoring Experiment-2 (GOME-2) instrument. We find that TROPOMI can reduce global uncertainties in SIF mapping by more than a factor of 2 with respect to GOME-2, which comes together with an approximately 5-fold improvement in spatial sampling. Finally, we discuss the potential of TROPOMI to map other important vegetation parameters at a global scale with moderate spatial resolution and short revisit time. Those include leaf photosynthetic pigments and proxies for canopy structure, which will complement SIF retrievals for a self-contained description of vegetation condition and functioning

24-Archaeological Investigations: Liberty Hyde Bailey Museum Site

This report documents an archaeological investigation conducted on the property of the Liberty Hyde Bailey Museum (LHBM) in South Haven, Van Buren County, MI, which was given the site number 20VA78. The homestead is the birthplace and childhood home of Dr. Liberty Hyde Bailey, Jr. (1858-1954), a naturalist, farmer, and Professor of Horticulture at Cornell University who gained prominence as a pioneer of the progressive farming movement in the late 19th and early 20th centuries. In the spring of 2012, John Stempien, then Director of the Liberty Hyde Bailey Museum, contacted Dr. LouAnn Wurst of Western Michigan University to request an archaeological investigation of the museum grounds. Museum personnel had located a picture dating to no later than the 1930s showing a small structure to the northwest of the main house that they speculated was a privy. Because the structure is no longer standing, the museum wished to know if any archaeological trace remained that would provide information about the building’s purpose and date. Archaeological excavations performed by Dr. Wurst and her students found no clear evidence of a foundation where the structure was located. However, the excavations did identify an archaeological feature and artifact deposits that provide new evidence of progressive social ideologies and farming techniques as well as insight into the everyday life of the occupants of the Liberty Hyde Bailey house

Finite automata with advice tapes

We define a model of advised computation by finite automata where the advice is provided on a separate tape. We consider several variants of the model where the advice is deterministic or randomized, the input tape head is allowed real-time, one-way, or two-way access, and the automaton is classical or quantum. We prove several separation results among these variants, demonstrate an infinite hierarchy of language classes recognized by automata with increasing advice lengths, and establish the relationships between this and the previously studied ways of providing advice to finite automata.Comment: Corrected typo

Towards Model Checking Executable UML Specifications in mCRL2

We describe a translation of a subset of executable UML (xUML) into the process algebraic specification language mCRL2. This subset includes class diagrams with class generalisations, and state machines with signal and change events. The choice of these xUML constructs is dictated by their use in the modelling of railway interlocking systems. The long-term goal is to verify safety properties of interlockings modelled in xUML using the mCRL2 and LTSmin toolsets. Initial verification of an interlocking toy example demonstrates that the safety properties of model instances depend crucially on the run-to-completion assumptions

Plasticity reveals hidden resistance to extinction under climate change in the global hotspot of salamander diversity

Extinction rates are predicted to rise exponentially under climate warming, but many of these predictions ignore physiological and behavioral plasticity that might buffer species from extinction. We evaluated the potential for physiological acclimatization and behavioral avoidance of poor climatic conditions to lower extinction risk under climate change in the global hotspot of salamander diversity, a region currently predicted to lose most of the salamander habitat due to warming. Our approach integrated experimental physiology and behavior into a mechanistic species distribution model to predict extinction risk based on an individual’s capacity to maintain energy balance with and without plasticity. We assessed the sensitivity of extinction risk to body size, behavioral strategies, limitations on energy intake, and physiological acclimatization of water loss and metabolic rate. The field and laboratory experiments indicated that salamanders readily acclimatize water loss rates and metabolic rates in ways that could maintain positive energy balance. Projections with plasticity reduced extinction risk by 72% under climate warming, especially in the core of their range. Further analyses revealed that juveniles might experience the greatest physiological stress under climate warming, but we identified specific physiological adaptations or plastic responses that could minimize the lethal physiological stress imposed on juveniles. We conclude that incorporating plasticity fundamentally alters ecological predictions under climate change by reducing extinction risk in the hotspot of salamander diversity