28 March 2019: Gent (Universiteit Gent, Faculty of Economics and Business Administration), workshop “Firm Heterogeneity in Technical Change”: Jin, Q., K. Kerstens, I. Van de Woestyne “Metafrontier Malmquist Productivity Index and The Price of a Convexification Strategy” (poster).
13 June 2019: London (University of London, Senate House) Sixteenth European Workshop on Efficiency and Productivity Measurement: Kerstens, K., C. O’Donnell, I. Van De Woestyne “The Cost Metafrontier is Nonconvex in the Outputs Since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
25 June 2019: Dublin (University College Dublin) Euro2019: Kerstens, K., C. O’Donnell, I. Van De Woestyne “The Cost Metafrontier is Nonconvex in the Outputs Since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
29 June 2019: Canterbury (University of Kent, Kent Business School) DEAIC: Kerstens, K., C. O’Donnell, I. Van De Woestyne “The Cost Metafrontier is Nonconvex in the Outputs Since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
9 June 2020: Coral Gables (University of Miami, Miami Business School), 11th North American Productivity Workshop, virtual keynote: Kerstens, K., J. Sadeghi, I. Van de Woestyne, J. Walden “Short-Run Johansen Frontier-Based Industry Models: Methodological Refinements and Empirical Illustration on Fisheries”.
24 October 2021: Anaheim (Anaheim Convention Center), 2021 INFORMS Annual Meeting: Kerstens, K., C. O’Donnell, I. Van De Woestyne “Estimating Nonconvex Cost Metafrontiers Correctly: The Price of a Convexification Strategy”.
28 October 2021: Tehran (Iranian DEA Society), 13th International Conference on Decision and Data Envelopment Analysis, virtual keynote: Chen, X., K. Kerstens, Q. Zhu “Exploring Horizontal Mergers in Swedish District Courts Using Convex and Nonconvex Technologies: Usefulness of a Conservative Approach”.
28 June 2022: Porto (Católica Porto Business School), Seventeenth European Workshop on Efficiency and Productivity Measurement: Ang, F., K. Kerstens, J. Sadeghi “Energy Productivity and Greenhouse Gas Emission Intensity in Dutch Dairy Farms: A Hicks-Moorsteen By-production Approach Under Convexity and Nonconvexity and Equivalence Results”.
8 Octobre 2022: Taipei (National Taiwan University & Taiwan Efficiency and Productivity Association), Asia Pacific Productivity Conference 2022 - Virtual Meeting: Ang, F., K. Kerstens, J. Sadeghi “Energy Productivity and Greenhouse Gas Emission Intensity in Dutch Dairy Farms: A Hicks-Moorsteen By-production Approach Under Convexity and Nonconvexity and Equivalence Results”.
17 November 2022 : Tabriz (Department of Mathematics, Azarbaijan Shahid Madani University) 15th International Conference of Iranian Operations Research Society, virtual keynote speaker : Ang, F., K. Kerstens, J. Sadeghi “Energy Productivity and Greenhouse Gas Emission Intensity in Dutch Dairy Farms: A Hicks-Moorsteen By-production Approach Under Convexity and Nonconvexity and Equivalence Results”.
14 June 2023: Coral Gables (University of Miami, Miami Business School), 11th North American Productivity Workshop: Chen, X., K. Kerstens, P.J. Kerstens “Two Nonconvex Variable Returns to Scale Technologies and Cost Functions: An Exploration on US Banking and Testing Convexity”.
5 August 2023: Altoona (Pennsylvania State University, Altoona), International Conference on Empirical Economics (virtual conference): Kerstens, K., C. O’Donnell, I. Van De Woestyne “When the Production Metafrontier is Nonconvex, then Cost Metafrontiers are Nonconvex in the Outputs: The Price of a Convexification Strategy”.
4 September 2023: Guildford (University of Surrey, Surrey Business School), International Conference on Data Envelopment Analysis DEA45: Badunenko, O., K. Kerstens, J. Sadeghi “Revenue Functions are Non-Concave in the Inputs when the Technology is Non-Convex: The Unbearable Lightness of Convexification”.
4 September 2023: Guildford (University of Surrey, Surrey Business School), International Conference on Data Envelopment Analysis DEA45: Dakpo, H.K., F. Ang, K. Kerstens “Cost Efficiency under Convex and Non-Convex Technologies: Does Output Aggregation Matter?“.
Participation in conferences (before 2019):
Australia: Brisbane (University of Queensland, Centre for Efficiency and Productivity Analysis (2014)).
Ottawa (DoubleTree by Hilton, Gatineau-Ottawa (2014));
Quebec (Le Concorde);
Toronto (University of Toronto (2004)).
China:
Tianjin (Nankai University);
Wuhan (Jianghan University).
Czech Republic: Prague (University of Economics (2017)).
Denmark: Copenhagen (KVL (1997, 1999)).
Finland: Helsinki (Aalto University School of Economics (2012, 2013); Grand Marina Congress Center (2015)).
France:
Aix-en-Provence (La Baume Les Aix (2006));
Lille (ESC (2008); IESEG School of Management (2007, 2008); Université de Lille 3 (2004, 2006));
Marq en Barœul (Maison des Professions (1998));
Marseille (CID/DESS, Université de la Méditerranée (1997));
Nantes (Université de Nantes (2006));
Paris (Ministère de l’Education Nationale, de la Recherche et de la Technologie (1998)).
Germany:
Braunschweig (TU Braunschweig (2015));
Wernigerode (Fachhochschule Harz (1998)).
Greece: Athens (Athens University of Economics and Business (2006, 2008); University of Athens (1993)).
Hungary: Budapest (Budapest University of Economic Sciences and Public Administration (2004)).
Iran: Karaj (Kharazmi University (2018)).
Italy:
Pisa (University of Pisa, School of Engineering (2009)).
Verona (University of Verona, School of Economics (2011))
South Korea: Seoul (Seoul National University, Global Education Center for Engineers (2018)).
Spain:
Barcelona (Universitat Politècnica de Catalunya (1997));
Oviedo (Universidad de Oviedo (2001, 2003)).
Sweden: Stockholm (Norra Latin Conference Center (1997)).
Taiwan: Taipei (Academia Sinica, Institute of Economics (2010); Soochow University, School of Business (2014)).
UK:
Birmingham (Aston University, Aston Business School (2018));
Coventry (Warwick Business School (1996));
Leicester (University of Leicester, School of Management (2009));
London (University of London, Senate House (2017));
St Andrews (School of Management, University of St Andrews (2013)).
USA:
Athens (University of Georgia (1994, 1996, 1998));
Coral Gables (University of Miami, Miami Business School (2018));
Corvallis (Oregon State University (2000));
Houston (Rice University, James Baker III Institute for Public Policy (2010, 2012));
New York (Stern School of Business (2006));
Santa Cruz (Southwest Fisheries Science Center (2012));
Schenectady (Union College (2000, 2002)).
Seminars presented (2019-2023):
23 January 2020: Paris (Leonard de Vinci Business School (EMLV)) seminar: Kerstens, K., C. O’Donnell, I. Van de Woestyne “Cost Metafrontiers are Nonconvex in the Outputs since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
15 June 2020: Ardabil (University of Mohaghegh Ardabili, International Relations Office) seminar (webinar): “COVID-19: Reflections of a European Academic Economist” and “Using COVID-19 Mortality to Select Among Hospital Plant Capacity Models: An Empirical Application to the Hubei Province”.
19 December 2022: Nanjing (Nanjing University of Information Science and Technology, School of Management Science and Engineering) seminar (webinar): Kerstens, K., C. O’Donnell, I. Van de Woestyne “Cost Metafrontiers are Nonconvex in the Outputs since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
21 December 2022: Nanjing (Nanjing University of Aeronautics and Astronautics, College of Economics and Management) seminar (webinar): Kerstens, K., C. O’Donnell, I. Van de Woestyne “Cost Metafrontiers are Nonconvex in the Outputs since the Metafrontier is Nonconvex: The Price of a Convexification Strategy”.
25 April 2023: Dijon (Burgundy School of Business), seminar: Kerstens, K., C. O’Donnell, I. Van de Woestyne “When the Production Metafrontier is Nonconvex, then Cost Metafrontiers are Nonconvex in the Outputs: The Price of a Convexification Strategy”.
1 June 2023: Liège (HEC, Université de Liège), seminar: Kerstens, K., C. O’Donnell, I. Van de Woestyne “When the Production Metafrontier is Nonconvex, then Cost Metafrontiers are Nonconvex in the Outputs: The Price of a Convexification Strategy”.
Seminars presented (before 2019):
Belgium:
Antwerp (Universiteit Antwerpen, Department of Economics - Department of Accounting and Finance (2013));
Gent (Universiteit Gent, Faculty of Economics and Business Administration (2005));
Louvain-la-Neuve (Université Catholique de Louvain, Institut de Statistique (1999); Université Catholique de Louvain, CORE (2009)).
China:
Harbin (School of Management, Harbin Institute of Technology (2013));
Hong Kong (Hong Kong Baptist University, School of Business (2006));
Shanghai (East China University of Science and Technology, School of Business (2016));
Tianjin (Tianjin University, College of Management and Economics (2016)).
Denmark: Esbjerg (University of Southern Denmark, Department of Environmental and Business Economics (2001)).
France:
Bordeaux (Université Montesquieu - Bordeaux IV, GREThA (2014, 2015, 2016));
Brest (Université de Bretagne Occidentale (UBO), Centre de Droit et d’Economie de la Mer (2004));
Lille (SKEMA Business School (2011); Université Catholique de Lille, LABORES (1995); Université des Sciences et Technologies Lille1, IAE (2004); Université des Sciences et Technologies Lille1, MEDEE (2005));
Berlin (Deutsches Institut für Wirtschaftsforschung (2012));
Kiel (Federal Dairy Research Centre, Institute of Food Industry Economics (2004));
Mannheim (ZEW (2008)).
Iran:
Shiraz (Islamic Azad University, Facility of Economics and Management (2018));
Tehran (Islamic Azad University, Department of Mathematics, Science and Research Branch (2018)).
Italy:
Verona (Università degli Studi di Verona, Dipartimento di Scienze Economiche (2006));
Venice (Università Ca’ Foscari, Department of Management (2018)).
Netherlands: Wageningen (Wageningen University, Mansholt Graduate School of Social Sciences (2005)).
New Zealand:
Auckland (University of Auckland, Business School (2014));
Palmerston North (Massey University, School of Economics & Finance (2014)).
Norway: Bergen (Norges Handelshøyskole - Norwegian School of Economics and Business Administration (1997)).
Spain:
Barcelona (Universitat Autònoma de Barcelona, Departament d’Economia de l’Empresa (2002, 2005, 2007, 2011));
Castelló de la Plana (Universitat Jaume I, Departament d’Economia & Departament de Finances I Comptabilitat (2005));
Girona (Universitat de Girona, Facultat de Ciències Econòmiques i Empresarials (2003));
Malaga (Universidad de Málaga, Dpto. Teoría e Historia Económica (2006));
Oviedo (Universidad de Oviedo, Departamento de Economía (2002));
Valencia (Universitat de Valencia, Departament d’Estructura Economica (2005)).
Taiwan: Taipei (National Chiao Tung University, Institute of Business and Management (2010, 2014); National Taiwan University, Department of Agricultural Economics (2007, 2008); National Taiwan University, Department of Economics (2007, 2008)).
UK:
Bangor (University of Wales, School for Business and Regional Development (2006));
Bath (University of Bath, Department of Economics (2011));
Canterbury (University of Kent, Canterbury Business School (1999));
Edinburgh (University of Edinburgh, Business School (2016));
Coventry (University of Warwick, Warwick Business School (1995, 2006));
London (Cass Business School (2008));
Nottingham (Nottingham University, Business School (2004)).