Miracle-dz/UniFAR-FTUs huggingface dataset:
The Rise in Household Spending Concentration∗

(Preliminary and Incomplete) Household consumption bundles look increasingly different from each other. Using detailed scanner data from 2004-2015, we document that households are concentrating more and more spending on their preferred products. These products, however, are not “superstars” that are purchased by everyone. Rather, household purchases are increasingly idiosyncratic. As a result, aggregate product concentration has actually declined even as product concentration within households has risen. This trend is pervasive across geographic locations and product categories and even holds within demographic and income groups. The growth in household concentration is associated with households purchasing new and dropping old products and is most rapid in retail chains that introduce the most new products. Further, those households with more concentrated product spending pay more for the products they purchase. These patterns suggest firms are increasingly able to introduce customized products or that consumers can better find them, and carry implications for market power and consumer welfare. ∗We thank David Argente for providing exceptional research assistance and Austan Goolsbee and Tom Wollmann for helpful comments and suggestions. Our analyses are calculated or derived based in part on data from The Nielsen Company (US), LLC and marketing databases provided through the Nielsen Datasets at the Kilts Center for Marketing Data Center at The University of Chicago Booth School of Business. The conclusions drawn from these Nielsen data are those of the researchers and do not reflect the views of Nielsen. Nielsen is not responsible for, had no role in, and was not involved in analyzing and preparing the results reported herein.
The PB2 Polymerase Host Adaptation Substitutions Prime Avian Indonesia Sub Clade 2.1 H5N1 Viruses for Infecting Humans

Significantly higher numbers of human infections with H5N1 virus have occurred in Indonesia and Egypt, compared with other affected areas, and it is speculated that there are specific viral factors for human infection with avian H5N1 viruses in these locations. We previously showed PB2-K526R is present in 80% of Indonesian H5N1 human isolates, which lack the more common PB2-E627K substitution. Testing the hypothesis that this mutation may prime avian H5N1 virus for human infection, we showed that: (1) K526R is rarely found in avian influenza viruses but was identified in H5N1 viruses 2–3 years after the virus emerged in Indonesia, coincident with the emergence of H5N1 human infections in Indonesia; (2) K526R is required for efficient replication of Indonesia H5N1 virus in mammalian cells in vitro and in vivo and reverse substitution to 526K in human isolates abolishes this ability; (3) Indonesian H5N1 virus, which contains K526R-PB2, is stable and does not further acquire E627K following replication in infected mice; and (4) virus containing K526R-PB2 shows no fitness deficit in avian species. These findings illustrate an important mechanism in which a host adaptive mutation that predisposes avian H5N1 virus towards infecting humans has arisen with the virus becoming prevalent in avian species prior to human infections occurring. A similar mechanism is observed in the Qinghai-lineage H5N1 viruses that have caused many human cases in Egypt; here, E627K predisposes towards human infections. Surveillance should focus on the detection of adaptation markers in avian strains that prime for human infection.
The discovery of a luminous, rapidly oscillating Ap star, HD 116114, with a 21‐minute pulsation period

The discovery of a new rapidly oscillating Ap star, HD 116114, with a pulsation period of 21 min, using high-resolution spectra obtained with the Ultraviolet-Visual Echelle Spectrograph at the European Southern Observatory's Very Large Telescope, is presented. The highest amplitudes of the radial velocity variations are between 50 and 125 m s -1 visible in the Eu II lines. The spectral lines of La II and the core of the Ha line have amplitudes of about 30 m s -1 . The frequency obtained for the oscillations is in good agreement with theoretical predictions of longer-period, evolved roAp stars. The distinction in luminosity between the roAp and noAp stars, and the suggestion that in all roAp stars the abundance of the second ions of Pr and Nd, relative to the abundance of the first ions, is anomalously high, need to be revised in the light of this discovery.
UNIVERSITÀ DEGLI STUDI DI SIENA QUADERNI DEL DIPARTIMENTO DI ECONOMIA POLITICA

Empirical research has shown that social interactions affect the use of public benefits, thus providing evidence in favor of the idea of “welfare cultures. ” In this paper we take the next crucial step by separately identifying the role of social stigma and information sharing in welfare participation, using Census data. We argue that the stigma vs. information distinction has possibly important consequences. Separate identification exploits the asymmetry between association and mere spatial proximity: we asume that while information is transmitted within groups, stigma works across groups as well. We also allow for heterogeneity of social effects across different race-ethnic groups and find non-trivial differences. We find that while the information channel is more important than stigma, White Americans appear to perceive stigma more from otherWhite Americans than by other races, and Black and Hispanic Americans appear to respond principally to stigma from external groups. JEL Classification Codes: I30, Z13.
An Analysis of the Effectiveness of Two Rainwater Harvesting Systems Located in Central Eastern Europe

Decentralized water systems are perceived as solutions that not only save water, but also as a way to partially or completely become independent from centralized suppliers. Taking this into account, an analysis of the effectiveness of rainwater harvesting systems (RWHS) for toilet flushing in existing academic facilities located in Poland and in Slovakia was carried out. The tests took into account the different volumes of storage tanks collecting rainwater. On the basis of two financial ratios, namely Net Present Value and Discounted Payback Period, the profitability of these systems was also assessed. The research was extended by the sensitivity analysis, which allowed determination of the impact of changes in individual cost components on the financial effectiveness of the investments considered. The results obtained clearly showed that the implementation of RWHS in the dormitory in Rzeszów was unprofitable for all tank capacities tested, and the payback period significantly exceeded the period of 30 years accepted for the analysis. Completely different results were obtained for RWHS in a dormitory located in the city of Košice, for which the financial ratios NPV (Net Present Value) and DPP (Discounted Payback Period) were very favorable. It was also confirmed by the results of the sensitivity analysis. The use of rainwater for toilet flushing caused that it was possible to achieve water savings of an average of 29% and 18%, respectively, for facilities located in Slovakia and Poland. The results of the research have a practical aspect and can provide an indication for potential investors and managers of academic facilities, similar to those analyzed in the article. Taking into account that in many countries water and sewage rates are significantly higher than in Poland and Slovakia, the cost-effectiveness of using the analyzed installation options in these countries could be even higher.
Land restoration in food security programmes: synergies with climate change mitigation

ABSTRACT Food-insecure households in many countries depend on international aid to alleviate acute shocks and chronic shortages. Some food security programmes (including Ethiopia’s Productive Safety Net Program–PSNP – which provides a case study for this article) have integrated aid in exchange for labour on public works to reduce long-term dependence by investing in the productive capacity and resilience of communities. Using this approach, Ethiopia has embarked upon an ambitious national programme of land restoration and sustainable land management. Although the intent was to reduce poverty, here we show that an unintended co-benefit is the climate-change mitigation from reduced greenhouse gas (GHG) emissions and increased landscape carbon stocks. The article first shows that the total reduction in net GHG emissions from PSNP’s land management at the national scale is estimated at 3.4 million Mg CO2e y−1 – approximately 1.5% of the emissions reductions in Ethiopia’s Nationally Determined Contribution for the Paris Agreement. The article then explores some of the opportunities and constraints to scaling up of this impact. Key policy insights Food security programmes (FSPs) can contribute to climate change mitigation by creating a vehicle for investment in land and ecosystem restoration. Maximizing mitigation, while enhancing but not compromising food security, requires that climate projections, and mitigation and adaptation responses should be mainstreamed into planning and implementation of FSPs at all levels. Cross-cutting oversight is required to integrate land restoration, climate policy, food security and disaster risk management into a coherent policy framework. Institutional barriers to optimal implementation should be addressed, such as incentive mechanisms that reward effort rather than results, and lack of centralized monitoring and evaluation of impacts on the physical environment. Project implementation can often be improved by adopting best management practices, such as using productive living livestock barriers where possible, and increasing the integration of agroforestry and non-timber forest products into landscape regeneration.
Sustaining small scale irrigation systems: the role of users

Small-scale irrigation schemes constructed for poverty reduction in developing countries are mostly managed by Water User Associations (WUAs). Users contributions in terms of labour towards resource maintenance is critical in sustaining the schemes. The amount of labour contributed depends on many factors, including users perceptions of the governance of WUAs and users willingness to cooperate in collective activities. In this paper we assess the effects of users governance perceptions and cooperativeness on maintenance contributions in northern Ghana. We use household survey data to create indicators of six governance dimensions, and estimate user s cooperativeness through lab-in-the-field experiments. OLS and Tobit regressions are used to respectively assess determinants of labour contributions and cooperativeness. We find that positive governance perceptions and cooperativeness generally affect labour contributions positively. Specifically, perceptions of transparency & cooperation affect labour contributions directly; and accountability and sustainable use both influence labour contributions directly and indirectly as mediated by the cooperativeness of users. Conflict management however has a negative impact on cooperativeness, and through that on labour contributions. We conclude that although better governance perceptions generally influence labour contributions to the maintenance of irrigation schemes positively, different dimensions differ in their direct as well as indirect contributions. Acknowledgement :
Surface-Controlled Photocatalysis and Chemical Sensing of TiO 2 , α-Fe 2 O 3 , and Cu 2 O Nanocrystals

A relatively new approach to the design of photocatalytic and gas sensing materials is to use the shape-controlled nanocrystals with well-defined facets exposed to light or gas molecules. An abrupt increase in a number of papers on the synthesis and characterization of metal oxide semiconductors such as a TiO2, α-Fe2O3, Cu2O of low-dimensionality, applied to surface-controlled photocatalysis and gas sensing, has been recently observed. The aim of this paper is to review the work performed in this field of research. Here, the focus is on the mechanism and processes that affect the growth of nanocrystals, their morphological, electrical, and optical properties and finally their photocatalytic as well as gas sensing performance.
Random scalar fields and hyperuniformity

Disordered many-particle hyperuniform systems are exotic amorphous states of matter that lie between crystals and liquids. Hyperuniform systems have attracted recent attention because they are endowed with novel transport and optical properties. Recently, the hyperuniformity concept has been generalized to characterize two-phase media, scalar fields, and random vector fields. In this paper, we devise methods to explicitly construct hyperuniform scalar fields. Specifically, we analyze spatial patterns generated from Gaussian random fields, which have been used to model the microwave background radiation and heterogeneous materials, the Cahn-Hilliard equation for spinodal decomposition, and Swift-Hohenberg equations that have been used to model emergent pattern formation, including Rayleigh-Benard convection. We show that the Gaussian random scalar fields can be constructed to be hyperuniform. We also numerically study the time evolution of spinodal decomposition patterns and demonstrate that they are hyper.
Consistent Rationalizability

Consistency of a binary relation requires any preference cycle to involve indifference only. It has been shown that consistency is necessary and sufficient for the existence of an ordering extension of a binary relation. It is therefore of interest to examine the rationalizability of choice functions by means of consistent relations. We describe the logical relationships between the different notions of rationalizability obtained if reflexivity or completeness are added to consistency. All but one such notion are characterized for general domains, and all are characterized for domains that contain all two-element subsets of the universal set.
Tax Policy and Retirement Savings

Governments around the world spend hundreds of billions of dollars subsidizing retirement savings through various tax preferences. This paper reviews the economics literature on retirement savings, with a particular focus on recent advances using behavioral economics and high-quality administrative data. This literature suggests that existing tax subsidies may not be an eﬀective policy to increase retirement savings for three reasons. First, tax subsidies appear to primarily aﬀect the allocation of savings across accounts, rather than the total amount of savings. Second, many savers are inattentive to tax policy when choosing the level of savings. Third, those savers most sensitive to tax subsidies are not those with the greatest savings inade-quacy. These same forces suggest that alternative policies focusing on behavioral “nudges,” such as automatic enrollment and access to payroll-deduction accounts, may be more eﬀective. sitive to tax subsidies are not those with the greatest savings inadequacy. These same forces suggest that alternative policies focusing on behavioral “nudges,” such as automatic enrollment and access to payroll-deduction accounts, may be more eﬀective.
Director Liability

This article contains the edited transcript of a forum on personal liability of directors held at Harvard Law School in November 2005. Eleven panelists offer their diverse views and perspectives on this subject. The participants in the panel, which is moderated by Lucian Bebchuk, are: Joseph Bachelder, Roel Campos, Byron Georgiou, Alan Hevesi, William Lerach, Robert Mendelsohn, Robert Monks, Toby Myerson, John Olson, Leo Strine, Jr., and John Wilcox.
The second conjugate algebra of the Fourier algebra of a locally compact group

Let G be a locally compact group and let VN(G) denote the von Neumann algebra generated by the left translations of G on L^G). Then VN(G)*, when regarded as the second conjugate space of the Fourier algebra of G, is a Banach algebra with the Arens product. We prove among other things that when G is amenable, VN(G)* is neither commutative nor semisimple unless G is finite. We study in detail the class of maximal regular left ideals in VN(G)*. We also show that if Gx and G2 are discrete groups, then G¡ and G2 are isomorphic if and only if VN(GX)* and VN(G2)* are isometric order isomorphic.
Dietary Zinc and Iron — Recent Perspectives Regarding Growth and Cognitive Development Moderate Zinc-Iron Deprivation Influences Behavior but Not Growth in Adolescent Rhesus Monkeys 1 , 2

Primate species demonstrate a prolonged period of development before reproductive maturity that includes distinctive periods of rapid growth in the late fetal, late infancy and early adolescent stages. Rhesus monkeys resemble humans in this discontinuous pattern of growth and also in its relationship to brain development. Studies of zinc deprivation in rhesus monkeys have suggested an important relationship among growth rate, nutrient status and behavioral performance in infancy as well as adolescence. Recently, moderate combined zinc and iron deprivation (intake 0.2 mg Zn and 0.8 mg Fe/d, compared with control intake of 2.9 mg Zn and 1.7 mg Fe/d) during the adolescent growth spurt (29–32 mo of age) of female rhesus monkeys (n 5 8/group) was shown to influence behavior without affecting growth. Behavioral assessments included the Continuous Performance Test, the Delayed Nonmatch to Sample Test and activity (measured with an actimeter). The behavioral syndrome was characterized by reduced activity, reduced participation in behavioral testing and slower response. These changes could be reversed or prevented to some extent by altering the diet to include tablets of powdered beef (adding ;1.7 mg Zn and 0.7 mg Fe to daily intake). The study suggests that behavior may be sensitive to the quality of the diet available during the period of rapid adolescent growth and development. J. Nutr. 130: 354S–357S,
Environmental Externalities, Median Voters, and the Multicentric City

This paper presents a new theory of the formation of a multicentric city and shows an example where median voters prevail in the social choice of land use patterns. To be specific, environmental externalities of work zones give an incentive to voters to form multiple subcenters in a city even in the absence of agglomeration economies. In addition, the land use pattern chosen closely follows the median voter's preferences under appropriately structured choice process. In this demonstration, zoning is as much the mechanism by which the internal structure of a city is organized as it is the one used to organize the metropolitan fabric of local governments in the Tiebout-Oates-Hamilton system.
Has 1997 Asian Crisis Increased Information Flows between International Markets?

The Asian crisis started on July 2, 1997 and caused turmoil in developed as well as emerging international stock markets. The objective of this paper is to analyse the movements and dynamic relationships among stock markets, together with their implications for information flows. We use the Morgan Stanley National and International Indexes (MSCI). These indexes refer to four geographic areas (Asia, Europe, North America and Latin America) for two homogeneous and non-overlapping time intervals. The econometric techniques used in this paper include the cointegration test, vector autoregression analysis, forecast error variance decomposition and impulse-response relationships. Our results show that: i) there are no multivariate cointegration relationships across markets, ii) the leadership role played by the U.S. became stronger after the crisis, iii) the response of Asian markets to external markets is more relevant than vice versa, especially after the crisis, iv) the degree of integration, in Phylaktis (1999) sense, between Asian and the rest of the international stock markets has increased after the crisis and, finally, v) the contagion effect determines significantly the dynamic relationships between international stock markets.
Accident Prevention and Damage Reduction in an Extended Liability Scheme

This study explores how an extended liability scheme affects a judgment-proof firm’s precaution levels to prevent accidents and reduce damage when the regulator cannot observe the firm’s private transactions. For this purpose, we incorporate the firm’s precautions to reduce damage into the model proposed by Hiriart and Martimort [1], who only investigated accident prevention. Then, we examine the optimal regulation of a firm that takes measures to reduce not only the probability of a serious environmental accident but also the extent of the damage of such an accident and analyze how the levels of these two types of efforts are affected by introducing an extended liability scheme. We expand the results of Hiriart and Martimort [1] by showing that extending liability to the firm’s stakeholders may improve social welfare by enhancing accident prevention efforts and by weakening damage reduction efforts even when the regulator cannot observe the private transactions between the firm and its stakeholders.
Job Creators

Job creation is perhaps the key political and economic issue of our time, yet this is one of only three papers to date to consider the nature of job creation amongst the self-employed. We develop a utility based model of self-employment which allows for the self-employed employees. The theory predicts that the higher the endowment of human capital the greater the likelihood of the entrepreneur employing additional labour, subject to overcoming any capital constraints. Empirical testing suggests that the decision to hire employees is related to work and lifetime experiences rather than academic achievements.
Effects of a strong magnetic field on the QCD flux tube

In this work we investigate the effect of an external magnetic field B on the shape of flux tubes in QCD by means of lattice simulations, performed with N_f=2+1 flavors of stout improved dynamical staggered quarks with physical masses. After having discussed some difficulties in the practical definition of the flux tube at B=0, we show that these ambiguities do not affect the determination of the flux tube modifications induced by the magnetic field. Different results are obtained depending on the relative orientations of the flux tube and of the magnetic field: they confirm that the magnetic field acts as transverse confinement catalyser and longitudinal confinement inhibitor; moreover, the flux tube itself loses its axial symmetry when it is not directed along the magnetic background.