IDEAS home Printed from https://ideas.repec.org/a/kap/ejlwec/v51y2021i1d10.1007_s10657-020-09676-0.html
   My bibliography  Save this article

Measuring the presence of organized crime across Italian provinces: a sensitivity analysis

Author

Listed:
  • Giovanni Bernardo

    (University of Palermo)

  • Irene Brunetti

    (National Institute for Public Policies Analysis)

  • Mehmet Pinar

    (Edge Hill University)

  • Thanasis Stengos

    (University of Guelph)

Abstract

The existing literature identifies different indicators to construct organized crime indices and places equal importance to different concepts of organized crime. This paper examines the sensitivity of organized crime across Italian provinces when different set of indicators and weights are used to combine crime indicators. Our findings suggest that there is a remarkable variation in the distribution of organized crime across Italian provinces based on the choice of indicators and the importance given to different crime indicators. It is also found that the relationship of organized crime with socioeconomic and political factors varies depending on the normative choices made in the construction of an organized crime index.

Suggested Citation

  • Giovanni Bernardo & Irene Brunetti & Mehmet Pinar & Thanasis Stengos, 2021. "Measuring the presence of organized crime across Italian provinces: a sensitivity analysis," European Journal of Law and Economics, Springer, vol. 51(1), pages 31-95, February.
  • Handle: RePEc:kap:ejlwec:v:51:y:2021:i:1:d:10.1007_s10657-020-09676-0
    DOI: 10.1007/s10657-020-09676-0
    as

    Download full text from publisher

    File URL: http://link.springer.com/10.1007/s10657-020-09676-0
    File Function: Abstract
    Download Restriction: Access to the full text of the articles in this series is restricted.

    File URL: https://libkey.io/10.1007/s10657-020-09676-0?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    References listed on IDEAS

    as
    1. Michele Battisti & Giovanni Bernardo & Andrea Mario Lavezzi & Giuseppe Maggio, 2019. "Shooting down the price: evidence from mafia homicides and housing market volatility," Working Paper series 19-05, Rimini Centre for Economic Analysis.
    2. Paolo Acciari & Alberto Polo & Giovanni L. Violante, 2022. "And Yet It Moves: Intergenerational Mobility in Italy," American Economic Journal: Applied Economics, American Economic Association, vol. 14(3), pages 118-163, July.
    3. Giuseppe De Feo & Giacomo Davide De Luca, 2017. "Mafia in the Ballot Box," American Economic Journal: Economic Policy, American Economic Association, vol. 9(3), pages 134-167, August.
    4. Backhaus, Jürgen G., 1979. "Defending organized crime? A note," Discussion Papers, Series I 120, University of Konstanz, Department of Economics.
    5. Gary S. Becker, 1974. "Crime and Punishment: An Economic Approach," NBER Chapters, in: Essays in the Economics of Crime and Punishment, pages 1-54, National Bureau of Economic Research, Inc.
    6. Maria Cracolici & Teodora Uberti, 2009. "Geographical distribution of crime in Italian provinces: a spatial econometric analysis," Review of Regional Research: Jahrbuch für Regionalwissenschaft, Springer;Gesellschaft für Regionalforschung (GfR), vol. 29(1), pages 1-28, February.
    7. Alberto Alesina & Salvatore Piccolo & Paolo Pinotti, 2019. "Organized Crime, Violence, and Politics," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 86(2), pages 457-499.
    8. Mehmet Pinar & Thanasis Stengos & Nikolas Topaloglou, 2013. "Measuring human development: a stochastic dominance approach," Journal of Economic Growth, Springer, vol. 18(1), pages 69-108, March.
    9. Pinotti, Paolo, 2020. "The credibility revolution in the empirical analysis of crime," CEPR Discussion Papers 14850, C.E.P.R. Discussion Papers.
    10. Michele Battisti & Andrea Mario Lavezzi & Lucio Masserini & Monica Pratesi, 2018. "Resisting the extortion racket: an empirical analysis," European Journal of Law and Economics, Springer, vol. 46(1), pages 1-37, August.
    11. Tomson Ogwang & Abdella Abdou, 2003. "The Choice of Principal Variables for Computing some Measures of Human Well-being," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 64(1), pages 139-152, October.
    12. Antonella Mennella, 2011. "La criminalit? organizzata quale intermediario nel mercato del lavoro," ARGOMENTI, FrancoAngeli Editore, vol. 2011(31), pages 65-105.
    13. Gianmarco Daniele & Benny Geys, 2015. "Organised Crime, Institutions and Political Quality: Empirical Evidence from Italian Municipalities," Economic Journal, Royal Economic Society, vol. 125(586), pages 233-255, August.
    14. Francesca Calamunci & Francesco Drago, 2020. "The Economic Impact of Organized Crime Infiltration in the Legal Economy: Evidence from the Judicial Administration of Organized Crime Firms," Italian Economic Journal: A Continuation of Rivista Italiana degli Economisti and Giornale degli Economisti, Springer;Società Italiana degli Economisti (Italian Economic Association), vol. 6(2), pages 275-297, July.
    15. Daniele, Gianmarco & Dipoppa, Gemma, 2017. "Mafia, elections and violence against politicians," Journal of Public Economics, Elsevier, vol. 154(C), pages 10-33.
    16. Thierry Post, 2003. "Empirical Tests for Stochastic Dominance Efficiency," Journal of Finance, American Finance Association, vol. 58(5), pages 1905-1932, October.
    17. Paolo Pinotti, 2015. "The Causes and Consequences of Organised Crime: Preliminary Evidence Across Countries," Economic Journal, Royal Economic Society, vol. 125(586), pages 158-174, August.
    18. Tahsin Mehdi, 2019. "Stochastic Dominance Approach to OECD’s Better Life Index," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 143(3), pages 917-954, June.
    19. Víctor Hugo Torres-Preciado & Mayrén Polanco-Gaytán & Miguel A. Tinoco-Zermeño, 2017. "Crime and regional economic growth in Mexico: A spatial perspective," Papers in Regional Science, Wiley Blackwell, vol. 96(3), pages 477-494, August.
    20. Mehmet Pinar & Thanasis Stengos & M. Ege Yazgan, 2015. "Measuring Human Development in the MENA Region," Emerging Markets Finance and Trade, Taylor & Francis Journals, vol. 51(6), pages 1179-1192, November.
    21. Daniele, Vittorio & Marani, Ugo, 2011. "Organized crime, the quality of local institutions and FDI in Italy: A panel data analysis," European Journal of Political Economy, Elsevier, vol. 27(1), pages 132-142, March.
    22. Scaillet, Olivier & Topaloglou, Nikolas, 2010. "Testing for Stochastic Dominance Efficiency," Journal of Business & Economic Statistics, American Statistical Association, vol. 28(1), pages 169-180.
    23. Thierry Post, 2003. "Empirical Tests for Stochastic Dominance Efficiency," Journal of Finance, American Finance Association, vol. 58(5), pages 1905-1931, October.
    24. Cruciani, Caterina & Giove, Silvio & Pinar, Mehmet & Sostero, Matteo, 2012. "Constructing the FEEM Sustainability Index: A Choquet-Integral Application," Climate Change and Sustainable Development 130550, Fondazione Eni Enrico Mattei (FEEM).
    25. Andrea Mario Lavezzi, 2008. "Economic structure and vulnerability to organised crime: Evidence from Sicily," Global Crime, Taylor & Francis Journals, vol. 9(3), pages 198-220, August.
    26. Drago, Francesco & Calamunci, Francesca, 2020. "The economic impact of organized crime infiltration in the legal economy: evidence from the judicial administration of organize," CEPR Discussion Papers 14326, C.E.P.R. Discussion Papers.
    27. Pinar, Mehmet & Stengos, Thanasis & Topaloglou, Nikolas, 2017. "Testing for the implicit weights of the dimensions of the Human Development Index using stochastic dominance," Economics Letters, Elsevier, vol. 161(C), pages 38-42.
    28. Marco Di Cataldo & Nicola Mastrorocco, 2022. "Organized Crime, Captured Politicians, and the Allocation of Public Resources [“Mafiaand Public Spending: Evidence on the Fiscal Multiplier from a Quasi-Experiment]," The Journal of Law, Economics, and Organization, Oxford University Press, vol. 38(3), pages 774-839.
    29. Annamaria Nifo & Gaetano Vecchione, 2014. "Do Institutions Play a Role in Skilled Migration? The Case of Italy," Regional Studies, Taylor & Francis Journals, vol. 48(10), pages 1628-1649, October.
    30. Jeroen Smits & Roel Steendijk, 2015. "The International Wealth Index (IWI)," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 122(1), pages 65-85, May.
    31. Peri Giovanni, 2004. "Socio-Cultural Variables and Economic Success: Evidence from Italian Provinces 1951-1991," The B.E. Journal of Macroeconomics, De Gruyter, vol. 4(1), pages 1-36, September.
    32. Roberto Ganau & Andrés Rodríguez†Pose, 2018. "Industrial clusters, organized crime, and productivity growth in Italian SMEs," Journal of Regional Science, Wiley Blackwell, vol. 58(2), pages 363-385, March.
    33. Daron Acemoglu & Giuseppe De Feo & Giacomo Davide De Luca, 2020. "Weak States: Causes and Consequences of the Sicilian Mafia," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 87(2), pages 537-581.
    34. Mustafa Caglayan & Alessandro Flamini & Babak Jahanshahi, 2017. "Organized Crime and Technology," DEM Working Papers Series 136, University of Pavia, Department of Economics and Management.
    35. Agliardi, Elettra & Agliardi, Rossella & Pinar, Mehmet & Stengos, Thanasis & Topaloglou, Nikolas, 2012. "A new country risk index for emerging markets: A stochastic dominance approach," Journal of Empirical Finance, Elsevier, vol. 19(5), pages 741-761.
    36. Koen Decancq & María Ana Lugo, 2013. "Weights in Multidimensional Indices of Wellbeing: An Overview," Econometric Reviews, Taylor & Francis Journals, vol. 32(1), pages 7-34, January.
    37. Ram, Rati, 1982. "Composite indices of physical quality of life, basic needs fulfilment, and income : A principal component representation," Journal of Development Economics, Elsevier, vol. 11(2), pages 227-247, October.
    38. Kugler, Maurice & Verdier, Thierry & Zenou, Yves, 2005. "Organized crime, corruption and punishment," Journal of Public Economics, Elsevier, vol. 89(9-10), pages 1639-1663, September.
    39. Timo Kuosmanen, 2004. "Efficient Diversification According to Stochastic Dominance Criteria," Management Science, INFORMS, vol. 50(10), pages 1390-1406, October.
    40. Agliardi, Elettra & Pinar, Mehmet & Stengos, Thanasis, 2014. "A sovereign risk index for the Eurozone based on stochastic dominance," Finance Research Letters, Elsevier, vol. 11(4), pages 375-384.
    41. Post, Thierry & Versijp, Philippe, 2007. "Multivariate Tests for Stochastic Dominance Efficiency of a Given Portfolio," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 42(2), pages 489-515, June.
    42. Oliver Linton & Thierry Post & Yoon‐Jae Whang, 2014. "Testing for the stochastic dominance efficiency of a given portfolio," Econometrics Journal, Royal Economic Society, vol. 17(2), pages 59-74, June.
    43. Ernesto Dal Bo & Rafael Di Tella, 2003. "Capture by Threat," Journal of Political Economy, University of Chicago Press, vol. 111(5), pages 1123-1152, October.
    44. Paolo Pinotti, 0. "The Credibility Revolution in the Empirical Analysis of Crime," Italian Economic Journal: A Continuation of Rivista Italiana degli Economisti and Giornale degli Economisti, Springer;Società Italiana degli Economisti (Italian Economic Association), vol. 0, pages 1-14.
    45. Elettra Agliardi & Mehmet Pinar & Thanasis Stengos, 2015. "An environmental degradation index based on stochastic dominance," Empirical Economics, Springer, vol. 48(1), pages 439-459, February.
    46. Amal Ray, 2008. "Measurement of social development: an international comparison," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 86(1), pages 1-46, March.
    47. Marco Dugato & Francesco Calderoni & Gian Maria Campedelli, 2020. "Measuring Organised Crime Presence at the Municipal Level," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 147(1), pages 237-261, January.
    48. Carlo Capuano & Massimiliano Giacalone, 2018. "Measuring Organized Crime: Statistical Indicators and Economics Aspects," EERI Research Paper Series EERI RP 2018/11, Economics and Econometrics Research Institute (EERI), Brussels.
    49. Alexeev, Michael & Janeba, Eckhard & Osborne, Stefan, 2004. "Taxation and evasion in the presence of extortion by organized crime," Journal of Comparative Economics, Elsevier, vol. 32(3), pages 375-387, September.
    50. Simon Rottenberg, 1973. "The Economics of Crime and Punishment," Books, American Enterprise Institute, number 920506, September.
    51. Paolo Pinotti, 2020. "The credibility revolution in the empirical analysis of crime," BAFFI CAREFIN Working Papers 20144, BAFFI CAREFIN, Centre for Applied Research on International Markets Banking Finance and Regulation, Universita' Bocconi, Milano, Italy.
    52. Salvatore Greco & Alessio Ishizaka & Menelaos Tasiou & Gianpiero Torrisi, 2019. "On the Methodological Framework of Composite Indices: A Review of the Issues of Weighting, Aggregation, and Robustness," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 141(1), pages 61-94, January.
    53. James E. Foster & Mark McGillivray & Suman Seth, 2013. "Composite Indices: Rank Robustness, Statistical Association, and Redundancy," Econometric Reviews, Taylor & Francis Journals, vol. 32(1), pages 35-56, January.
    54. Francesco Calderoni, 2011. "Where is the mafia in Italy? Measuring the presence of the mafia across Italian provinces," Global Crime, Taylor & Francis Journals, vol. 12(1), pages 41-69, February.
    55. Vittorio, Daniele, 2009. "Organized crime and regional development. A review of the Italian case," MPRA Paper 16547, University Library of Munich, Germany.
    56. Mark McGillivray, 2005. "Measuring Non‐Economic Well‐Being Achievement," Review of Income and Wealth, International Association for Research in Income and Wealth, vol. 51(2), pages 337-364, June.
    57. Paolo Pinotti, 2015. "The Economic Costs of Organised Crime: Evidence from Southern Italy," Economic Journal, Royal Economic Society, vol. 125(586), pages 203-232, August.
    58. Mehmet Pinar & Joniada Milla & Thanasis Stengos, 2019. "Sensitivity of university rankings: implications of stochastic dominance efficiency analysis," Education Economics, Taylor & Francis Journals, vol. 27(1), pages 75-92, January.
    59. Mehmet Pinar, 2015. "Measuring world governance: revisiting the institutions hypothesis," Empirical Economics, Springer, vol. 48(2), pages 747-778, March.
    60. Gary S. Becker & Kevin M. Murphy & Michael Grossman, 2006. "The Market for Illegal Goods: The Case of Drugs," Journal of Political Economy, University of Chicago Press, vol. 114(1), pages 38-60, February.
    61. Kyriakos C. Neanidis & Maria Paola Rana & Keith Blackburn, 2017. "An empirical analysis of organized crime, corruption and economic growth," Annals of Finance, Springer, vol. 13(3), pages 273-298, August.
    62. Paolo Pinotti, 2020. "The Credibility Revolution in the Empirical Analysis of Crime," Italian Economic Journal: A Continuation of Rivista Italiana degli Economisti and Giornale degli Economisti, Springer;Società Italiana degli Economisti (Italian Economic Association), vol. 6(2), pages 207-220, July.
    63. Thierry Post & Valerio Potì, 2017. "Portfolio Analysis Using Stochastic Dominance, Relative Entropy, and Empirical Likelihood," Management Science, INFORMS, vol. 63(1), pages 153-165, January.
    64. Arvanitis, Stelios & Topaloglou, Nikolas, 2017. "Testing for prospect and Markowitz stochastic dominance efficiency," Journal of Econometrics, Elsevier, vol. 198(2), pages 253-270.
    65. Fang, Yi & Post, Thierry, 2017. "Higher-degree stochastic dominance optimality and efficiency," European Journal of Operational Research, Elsevier, vol. 261(3), pages 984-993.
    66. Daron Acemoglu & James A. Robinson & Rafael J. Santos, 2013. "The Monopoly Of Violence: Evidence From Colombia," Journal of the European Economic Association, European Economic Association, vol. 11, pages 5-44, January.
    67. Stelios Arvanitis & Nikolas Topalogou, 2017. "Testing for Prospect and Markowitz stochastic dominance efficiency," Working Papers 201701, Athens University Of Economics and Business, Department of Economics.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Boeri, Filippo & Di Cataldo, Marco & Pietrostefani, Elisabetta, 2022. "Localised effects of re-allocated real estate mafia assets," LSE Research Online Documents on Economics 116682, London School of Economics and Political Science, LSE Library.

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Mehmet Pinar & Thanasis Stengos & Nikolas Topaloglou, 2022. "Stochastic dominance spanning and augmenting the human development index with institutional quality," Annals of Operations Research, Springer, vol. 315(1), pages 341-369, August.
    2. Pinar, Mehmet & Stengos, Thanasis & Topaloglou, Nikolas, 2020. "On the construction of a feasible range of multidimensional poverty under benchmark weight uncertainty," European Journal of Operational Research, Elsevier, vol. 281(2), pages 415-427.
    3. Francesca M. Calamunci & Livio Ferrante & Rossana Scebba, 2022. "Closed for mafia: Evidence from the removal of mafia firms on commercial property values," Journal of Regional Science, Wiley Blackwell, vol. 62(5), pages 1487-1511, November.
    4. Tahsin Mehdi, 2019. "Stochastic Dominance Approach to OECD’s Better Life Index," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 143(3), pages 917-954, June.
    5. Marco Dugato & Francesco Calderoni & Gian Maria Campedelli, 2020. "Measuring Organised Crime Presence at the Municipal Level," Social Indicators Research: An International and Interdisciplinary Journal for Quality-of-Life Measurement, Springer, vol. 147(1), pages 237-261, January.
    6. Caglayan, Mustafa & Flamini, Alessandro & Jahanshahi, Babak, 2021. "Hindering human capital accumulation: A hidden cost of the silent mafia?," Journal of Economic Behavior & Organization, Elsevier, vol. 188(C), pages 828-845.
    7. Mehmet Pinar & Thanasis Stengos & M. Ege Yazgan, 2018. "Quantile forecast combination using stochastic dominance," Empirical Economics, Springer, vol. 55(4), pages 1717-1755, December.
    8. Francesca Maria Calamunci & Federico Fabio Frattini, 2023. "When Crime Tears Communities Apart: Social Capital and Organised Crime," Working Papers 2023.08, Fondazione Eni Enrico Mattei.
    9. Forgione, Antonio Fabio & Migliardo, Carlo, 2023. "Mafia risk perception: Evaluating the effect of organized crime on firm technical efficiency and investment proclivity," Socio-Economic Planning Sciences, Elsevier, vol. 88(C).
    10. Paolo Pinotti, 0. "The Credibility Revolution in the Empirical Analysis of Crime," Italian Economic Journal: A Continuation of Rivista Italiana degli Economisti and Giornale degli Economisti, Springer;Società Italiana degli Economisti (Italian Economic Association), vol. 0, pages 1-14.
    11. Tamara Fioroni & Andrea Mario Lavezzi & Giovanni Trovato, 2023. "Organized Crime, Corruption and Economic Growth," Discussion Papers 2023/298, Dipartimento di Economia e Management (DEM), University of Pisa, Pisa, Italy.
    12. Boeri, Filippo & Di Cataldo, Marco & Pietrostefani, Elisabetta, 2022. "Localised effects of re-allocated real estate mafia assets," LSE Research Online Documents on Economics 116682, London School of Economics and Political Science, LSE Library.
    13. Nicola Mastrorocco, 2018. "Organised Crime, Captured Politicians and the Allocation of Public Resources," Trinity Economics Papers tep1018, Trinity College Dublin, Department of Economics.
    14. Paolo Pinotti, 2020. "The Credibility Revolution in the Empirical Analysis of Crime," Italian Economic Journal: A Continuation of Rivista Italiana degli Economisti and Giornale degli Economisti, Springer;Società Italiana degli Economisti (Italian Economic Association), vol. 6(2), pages 207-220, July.
    15. Mehmet Pinar, 2015. "Measuring world governance: revisiting the institutions hypothesis," Empirical Economics, Springer, vol. 48(2), pages 747-778, March.
    16. Paolo Buonanno & Irene Ferrari & Alessandro Saia, 2023. "ALL IS NOT LOST: Organized Crime and Social Capital Formation," Working Papers 2023: 16, Department of Economics, University of Venice "Ca' Foscari", revised 2024.
    17. Tahsin Mehdi, 2019. "Stochastic Dominance Approach to Measuring Child Development," Child Indicators Research, Springer;The International Society of Child Indicators (ISCI), vol. 12(5), pages 1567-1588, October.
    18. Arvanitis, Stelios & Scaillet, Olivier & Topaloglou, Nikolas, 2020. "Spanning tests for Markowitz stochastic dominance," Journal of Econometrics, Elsevier, vol. 217(2), pages 291-311.
    19. Daniele, Gianmarco, 2019. "Strike one to educate one hundred: Organized crime, political selection and politicians’ ability," Journal of Economic Behavior & Organization, Elsevier, vol. 159(C), pages 650-662.
    20. Pinotti, Paolo, 2020. "The credibility revolution in the empirical analysis of crime," CEPR Discussion Papers 14850, C.E.P.R. Discussion Papers.

    More about this item

    Keywords

    Organized crime; Composite index; Italian provinces; Mafia; Stochastic dominance;
    All these keywords.

    JEL classification:

    • C12 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General - - - Hypothesis Testing: General
    • C14 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General - - - Semiparametric and Nonparametric Methods: General
    • C15 - Mathematical and Quantitative Methods - - Econometric and Statistical Methods and Methodology: General - - - Statistical Simulation Methods: General
    • K49 - Law and Economics - - Legal Procedure, the Legal System, and Illegal Behavior - - - Other
    • R58 - Urban, Rural, Regional, Real Estate, and Transportation Economics - - Regional Government Analysis - - - Regional Development Planning and Policy

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:kap:ejlwec:v:51:y:2021:i:1:d:10.1007_s10657-020-09676-0. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.springer.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.