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1. Estimating the Influence of Financial Aid on Student Retention: A Discrete-Choice Propensity Score-Matching Model

Author

University of Arkansas, Education Working Paper Archive and Herzog, Serge

Abstract

The greatest limitation in establishing causality in observational studies on the effect of financial aid is the presence of endogeneity or selection bias associated with aid status. To control for this statistical confoundedness that besets the research corpus to date, this study estimates the effect of financial aid on freshmen retention at a moderately selective, public university using propensity score-matching in multi-stage regression analyses. The correlational pattern that emerged from twenty-four logit models suggests higher-income students accrue a retention benefit from financial aid, unlike low-income students, net of first-year academic experience and type and amount of aid received. Conversely, retention of low-income freshmen is more likely due to academic performance compared to those from high-income background. Findings on the effect of aid are consistent with the economics of moral hazard and unobservable behavior. (Contains 6 footnotes, 8 tables, and 2 figures.)

Published
2008

2. What Do Cost Functions Tell Us about the Cost of an Adequate Education?

Author

University of Arkansas, Education Working Paper Archive, Costrell, Robert M., Hanushek, Eric, and Loeb, Susanna

Abstract

Econometric cost functions have begun to appear in education adequacy cases with greater frequency. Cost functions are superficially attractive because they give the impression of objectivity, holding out the promise of scientifically estimating the cost of achieving specified levels of performance from actual data on spending. By contrast, the opinions of education stakeholders form the basis of the most common approach to estimating the cost of adequacy, the professional-judgment method. The problem is that education cost functions do not in fact tell us the cost of achieving any specified level of performance. Instead, they provide estimates of average spending for districts of given characteristics and current performance. It is a huge and unwarranted stretch to go from this interpretation of regression results to the claim that they provide estimates of the minimum cost of achieving current performance levels, and it is even more problematic to extrapolate the cost of achieving at higher levels. In this paper we review the cost function technique and provide evidence that draws into question the usefulness of the cost function approach for estimating the cost of an adequate education. (Contains 28 footnotes and 7 figures.) [Funding for this paper was provided by the Missouri Show-Me Institute.]

Published
2008

3. Engaging Ecosystems

Author

Duncan, Susan, Papers, Jerry, and Franzen, Woody

Abstract

Vertical connections, constructed using inquiry, give students the skills to reach new heights in both their academic and local communities. In this article, the authors present inquiry projects, developed by middle level teachers, to ensure that students use higher-level thinking skills to improve the community. Each project is connected to the previous year's to give students a deeper understanding of how research can help citizens build a sustainable community. Teachers work together to plan field studies and guide students in presenting their findings to others in the community using models, PowerPoint presentations, a web accessible database, and reports from field investigations. The projects are as follows: (1) healthy marine ecosystems--sixth grade; (2) interdisciplinary science: biodiversity and development--seventh grade; and (3) collaborating to create a better biosphere--eighth grade. (Contains 1 figure and 4 online resources.)

Published
2006

4. Water Use Efficiency (WUE) across scales: From genes to landscape

Author

Vincent Vadez, Raphael Pilloni, Alexandre Grondin, Amir Hajjarpoor, Hatem Belhouchette, Youssef Brouziyne, Ghani Chehbouni, Mohamed Hakim Kharrou, Rim Zitouna-Chebbi, Insaf Mekki, Jérôme Molénat, Frédéric Jacob, Jérôme Bossuet, Diversité, adaptation, développement des plantes (UMR DIADE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Université de Montpellier (UM), International Crops Research Institute for the Semi-Arid Tropics [Inde] (ICRISAT), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Centre d'Etude Regional Pour l'Amelioration de l'Adaptation A la Secheresse (CERAAS), Institut Sénégalais de Recherches Agricoles [Dakar] (ISRA), LMI Adaptation des Plantes et microorganismes associés aux Stress Environnementaux [Dakar] (LAPSE), Institut de Recherche pour le Développement (IRD), Agrosystèmes Biodiversifiés (UMR ABSys), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre International de Hautes Etudes Agronomiques Méditerranéennes - Institut Agronomique Méditerranéen de Montpellier (CIHEAM-IAMM), Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), International Water Management Institute, MENA Office (IWMI), Université Mohammed VI Polytechnique [Ben Guerir] (UM6P), International Water Research Institute (IWRI), Institut National de Recherche en Génie Rural Eaux et Forêts (INRGREF), Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF)-Institution de la Recherche et de l'Enseignement Supérieur Agricoles [Tunis] (IRESA), Laboratoire d'étude des Interactions Sol - Agrosystème - Hydrosystème (UMR LISAH), Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Independent Consultant, The paper was written and supported under the Make Our Planet Great Again (MOPGA) ICARUS project (Improve Crops in Arid Regions and future climates) funded by the Agence Nationale de la Recherche (ANR, grant ANR-17-MPGA-0011), and written in the scope and with the support of the ClimBeR initiative of the CGIAR, itself supported by the France-CGIAR action plan on Climate Change., ANR-17-MPGA-0011,ICARUS,Improve Crops in Arid Regions and future climates(2017), Centre International de Hautes Etudes Agronomiques Méditerranéennes - Institut Agronomique Méditerranéen de Montpellier (CIHEAM-IAMM), Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM), and Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro

Subjects
CLIMATIC CHANGE, Physiology, PAYSAGE AGRICOLE, WATER MANAGEMENT, MODELS, [SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy, CROPPING SYSTEMS, UTILISATION DE L'EAU, Plant Science, drought, GESTION DES EAUX, EXPLOITATION AGRICOLE, AGRICULTURAL LANDSCAPE, MODELE, FARMS, farming systems, WUE, ECHELLE SPATIALE, SECHERESSE, [SDE.IE]Environmental Sciences/Environmental Engineering, SYSTEME DE CULTURE, TRANSPIRATION, [SDV.SA.AEP]Life Sciences [q-bio]/Agricultural sciences/Agriculture, economy and politics, food security, WATER USE, landscape, WATER USE EFFICIENCY, landscapewater use efficiency, EFFICIENCE D'UTILISATION DE L'EAU, climate change, CHANGEMENT CLIMATIQUE, breeding, SPATIAL SCALE, farming system, crop breeding, [SDV.EE.BIO]Life Sciences [q-bio]/Ecology, environment/Bioclimatology
Abstract

International audience; Highlights:This paper reviews ways to improve water use efficiency beyond the plant level, across time and space scales, from cells, organs, and plants, to field, farm, and landscape.Abstract:Water scarcity will be one of the main issues of the 21 st century, because of competing needs between civil, industrial, and agriculture use. While agriculture is the largest user of water, its share is bound to decrease as societies develop. Clearly, agriculture needs to become more water efficient. Improving water use efficiency (WUE) at the plant level is important although there is a long way into translating this at the farm/landscape level. As we move up from a cell/organ/plant scale to more integrated scales such as plot, field, farm system, and landscape, other factors need to be considered, including trade-offs, to possibly improve WUE. These include choices of crop variety/species, farm management, landscape design, infrastructure development, ecosystem functions, where human decisions matter. This review is a cross-disciplinary attempt to analyze ways to address WUE at these different scales where metrics of analysis are defined and trade-offs considered. The equations in this perspective paper use similar metrics across scales for an easier connection and are developed to highlight which levers, at different scales, can improve WUE. We also refer to models operating at these different scales to assess WUE. While our entry point is plants and crops, we scale up the analysis of WUE to farm systems and landscapes.

Published
2023

5. Data-Driven Approach to Grade Change Scheduling Optimization in a Paper Machine

Author

Tewodros Deneke, Teemu J. Ikonen, Hossein Mostafaei, Jason Kramb, Iiro Harjunkoski, Keijo Heljanko, Department of Chemical and Metallurgical Engineering, Process Control and Automation, UPM Communication Papers, University of Helsinki, Aalto-yliopisto, Aalto University, Department of Computer Science, and Helsinki Institute for Information Technology

Subjects
Decision support system, business.product_category, Computer science, CONTINUOUS-TIME, General Chemical Engineering, MODELS, Scheduling (production processes), 215 Chemical engineering, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, FRAMEWORK, Industrial engineering, Industrial and Manufacturing Engineering, Scheduling (computing), Data-driven, Paper machine, 020401 chemical engineering, SCOPE, 0204 chemical engineering, 0210 nano-technology, business, Computer Science::Operating Systems
Abstract

This paper proposes an efficient decision support tool for the optimal production scheduling of a variety of paper grades in a paper machine. The tool is based on a continuous-time scheduling model and generalized disjunctive programming. As the full-space scheduling model corresponds to a large-scale mixed integer linear programming model, we apply data analytics techniques to reduce the size of the decision space, which has a profound impact on the computational efficiency of the model and enables us to support the solution of large-scale problems. The data-driven model is based on an automated method of identifying the forbidden and recommended paper grade sequences, as well as the changeover durations between two paper grades. The results from a real industrial case study show that the data-driven model leads to good results in terms of both solution quality and CPU time in comparison to the full-space model.

Published
2020

6. Hydrophobic properties conferred to Kraft pulp by a laccase-catalysed treatment with lauryl gallate

Author

Céline Reynaud, Michel Petit-Conil, Sandra Tapin-Lingua, Graziano Elegir, Stéphanie Baumberger, Intechfibers, FCBA, New Mat Div, Domaine Univ, Paper Div, Innovhub ssi, Intechfibers, Ctr Tech Papier, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, ENCELPA, ANRT, and Institut Technologique Forêt Cellulose Bois-construction Ameublement (FCBA)

Subjects
Paper, [SDV.SA]Life Sciences [q-bio]/Agricultural sciences, 0106 biological sciences, Absorption of water, Hydrophobicity, MODELS, Bioengineering, Kappa number, 01 natural sciences, Applied Microbiology and Biotechnology, Acetone, GALLIC ACID, chemistry.chemical_compound, Adsorption, 010608 biotechnology, Organic chemistry, Gallic acid, Laccase, 010405 organic chemistry, Green Chemistry Technology, General Medicine, Wood, 0104 chemical sciences, chemistry, Kraft process, Papermaking, Lauryl gallate, Dodecanol, Hydrophobic and Hydrophilic Interactions, Biotechnology
Abstract

Hydrophobic properties were conferred to a high-lignin-content Kraft pulp by a laccase-catalysed treatment in the presence of lauryl gallate (LG). The treatment resulted in a two-fold increase in contact angle and conferred water absorption resistance to the pulp. Kappa number was increased, indicating that some phenolic compounds were incorporated in the pulp. A control treatment with LG alone did not affect water absorption, demonstrating that laccase was essential to attain these new properties. The loss of hydrophobicity after an acetone Soxhlet extraction highlighted that adsorbed acetone-soluble compounds played a key role in the properties. GC-FID and HPSEC-UV analysis of the acetone extract indicated the formation of dodecanol and different phenolic oligomers. SEM images showed the treatment-induced changes in the fibre network. Additional experiments with various reaction times and reactant concentrations highlighted the role of LG oxidation products in the introduction of absorption resistance. (C) 2013 Elsevier B.V. All rights reserved.

Published
2013

7. Economics: Between Prediction and Criticism

Author

Gilboa, Itzhak, Postlewaite, Andrew, Samuelson, Larry, Schmeidler, David, Haldemann, Antoine, Tel Aviv University [Tel Aviv], University of Pennsylvania [Philadelphia], Department of Economics, Yale University [New Haven], and HEC Paris Research Paper Series

Subjects
Economic Modeling, Models, JEL: B - History of Economic Thought, Methodology, and Heterodox Approaches/B.B4 - Economic Methodology/B.B4.B41 - Economic Methodology, jel:B40, jel:B41, Methodology, [SHS.GESTION]Humanities and Social Sciences/Business administration, JEL: B - History of Economic Thought, Methodology, and Heterodox Approaches/B.B4 - Economic Methodology/B.B4.B40 - General, [SHS.GESTION] Humanities and Social Sciences/Business administration, Methodology, Models, Economic modeling
Abstract

We suggest that one way in which economic analysis is useful is by offering a critique of reasoning. According to this view, economic theory may be useful not only by providing predictions, but also by pointing out weaknesses of arguments. It is argued that, when a theory requires a non-trivial act of interpretation, it's roles in producing predictions and offering critiques vary in a substantial way. We offer a formal model i which these different roles can be captured.

Published
2016