IDEAS home Printed from https://ideas.repec.org/a/sae/sagope/v14y2024i2p21582440241257591.html
   My bibliography  Save this article

Deciphering Social Commerce: A Quantitative Meta-Analysis Measuring the Social, Technological, and Motivational Dimensions of Consumer Purchase Intentions

Author

Listed:
  • Jian Wang
  • Fakhar Shahzad

Abstract

Social commerce, as a new business model, is becoming increasingly critical. Even though a large amount of literature examines the determinants of consumer purchase intentions, the evidence needs to be more balanced. Therefore, this quantitative meta-analysis aims to compare and confirm the research results on social commerce from 2010 to 2022 to reconcile the conflicting results. The results indicate that emotional support, relationship quality, and perceived value positively and strongly correlate with purchase intention. In contrast, technical factors (such as Information quality, System quality, and Service quality) exhibited a small influence. Also, we found that culture moderated the relationships between consumer purchase intentions and their causes, except for information support and interactivity. The moderator analysis suggests technical and motivational factors are more important in Eastern than Western culture. For Social factors, the effect size of Western culture is bigger on the relationships of social support, information support, and Emotional support. This study gives insight into the integration factors that affect the breadth and depth of customers’ buying plans, as well as future directions for research that will help management make decisions.

Suggested Citation

  • Jian Wang & Fakhar Shahzad, 2024. "Deciphering Social Commerce: A Quantitative Meta-Analysis Measuring the Social, Technological, and Motivational Dimensions of Consumer Purchase Intentions," SAGE Open, , vol. 14(2), pages 21582440241, June.
    • Handle: RePEc:sae:sagope:v:14:y:2024:i:2:p:21582440241257591
    DOI: 10.1177/21582440241257591
    as

    Download full text from publisher

    File URL: https://journals.sagepub.com/doi/10.1177/21582440241257591
    Download Restriction: no
    File URL: https://libkey.io/10.1177/21582440241257591?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
    ---><---

    References listed on IDEAS

    as
    1. Yeon, Jewoo & Park, Inyoung & Lee, Daeho, 2019. "What creates trust and who gets loyalty in social commerce?," Journal of Retailing and Consumer Services, Elsevier, vol. 50(C), pages 138-144.
    2. Kim, Sanghyun & Park, Hyunsun, 2013. "Effects of various characteristics of social commerce (s-commerce) on consumers’ trust and trust performance," International Journal of Information Management, Elsevier, vol. 33(2), pages 318-332.
    3. Onofrei, George & Filieri, Raffaele & Kennedy, Lorraine, 2022. "Social media interactions, purchase intention, and behavioural engagement: The mediating role of source and content factors," Journal of Business Research, Elsevier, vol. 142(C), pages 100-112.
    4. Leong, Lai-Ying & Hew, Teck-Soon & Ooi, Keng-Boon & Chong, Alain Yee-Loong, 2020. "Predicting the antecedents of trust in social commerce – A hybrid structural equation modeling with neural network approach," Journal of Business Research, Elsevier, vol. 110(C), pages 24-40.
    5. Mei-Hui Chen & Kune-Muh Tsai, 2020. "An Empirical Study of Brand Fan Page Engagement Behaviors," Sustainability, MDPI, vol. 12(1), pages 1-19, January.
    6. Jeyaraj, Anand & Dwivedi, Yogesh K., 2020. "Meta-analysis in information systems research: Review and recommendations," International Journal of Information Management, Elsevier, vol. 55(C).
    7. Yahia, Imene Ben & Al-Neama, Nasser & Kerbache, Laoucine, 2018. "Investigating the drivers for social commerce in social media platforms: Importance of trust, social support and the platform perceived usage," Journal of Retailing and Consumer Services, Elsevier, vol. 41(C), pages 11-19.
    8. Wang, Xiao-Wu & Cao, Yu-Mei & Park, Cheol, 2019. "The relationships among community experience, community commitment, brand attitude, and purchase intention in social media," International Journal of Information Management, Elsevier, vol. 49(C), pages 475-488.
    9. Md. Alamgir Hossain & Nusrat Jahan & Minho Kim, 2020. "A Mediation and Moderation Model of Social Support, Relationship Quality and Social Commerce Intention," Sustainability, MDPI, vol. 12(23), pages 1-13, November.
    10. Cheng, Xusen & Gu, Yu & Shen, Jia, 2019. "An integrated view of particularized trust in social commerce: An empirical investigation," International Journal of Information Management, Elsevier, vol. 45(C), pages 1-12.
    11. Min-Sook Park & Jong-Kuk Shin & Yong Ju, 2014. "The Effect of Online Social Network Characteristics on Consumer Purchasing Intention of Social Deals," Global Economic Review, Taylor & Francis Journals, vol. 43(1), pages 25-41, March.
    12. Hsin-Hui Lee & Chia-Hsing Liang & Shu-Yi Liao & Han-Shen Chen, 2019. "Analyzing the Intention of Consumer Purchasing Behaviors in Relation to Internet Memes Using VAB Model," Sustainability, MDPI, vol. 11(20), pages 1-12, October.
    13. Li, Chia-Ying, 2019. "How social commerce constructs influence customers' social shopping intention? An empirical study of a social commerce website," Technological Forecasting and Social Change, Elsevier, vol. 144(C), pages 282-294.
    14. Kyung-Joon Kwon & Li-Wei Mai & Norman Peng, 2020. "Determinants of consumers’ intentions to share knowledge and intentions to purchase on s-commerce sites: incorporating attitudes toward persuasion attempts into a social exchange model," Eurasian Business Review, Springer;Eurasia Business and Economics Society, vol. 10(1), pages 157-183, March.
    15. Yuyang Zhao & Fernando Bacao, 2021. "How Does Gender Moderate Customer Intention of Shopping via Live-Streaming Apps during the COVID-19 Pandemic Lockdown Period?," IJERPH, MDPI, vol. 18(24), pages 1-24, December.
    16. Nadeem, Waqar & Khani, Amir H. & Schultz, Carsten D. & Adam, Nawal Abdalla & Attar, Razaz Waheeb & Hajli, Nick, 2020. "How social presence drives commitment and loyalty with online brand communities? the role of social commerce trust," Journal of Retailing and Consumer Services, Elsevier, vol. 55(C).
    17. Sokolova, Karina & Kefi, Hajer, 2020. "Instagram and YouTube bloggers promote it, why should I buy? How credibility and parasocial interaction influence purchase intentions," Journal of Retailing and Consumer Services, Elsevier, vol. 53(C).
    18. Zheng, Xiabing & Men, Jinqi & Xiang, Li & Yang, Feng, 2020. "Role of technology attraction and parasocial interaction in social shopping websites," International Journal of Information Management, Elsevier, vol. 51(C).
    19. Fu, Jen-Ruei & Lu, I-Wei & Chen, Jessica H.F. & Farn, Cheng-Kiang, 2020. "Investigating consumers’ online social shopping intention: An information processing perspective," International Journal of Information Management, Elsevier, vol. 54(C).
    20. Klein, Andreas & Sharma, Varinder M., 2022. "Consumer decision-making styles, involvement, and the intention to participate in online group buying," Journal of Retailing and Consumer Services, Elsevier, vol. 64(C).
    21. Yu Xiang Xia & Seong Wook Chae, 2021. "Sustainable Development of Online Group-Buying Websites: An Integrated Perspective of ECM and Relationship Marketing," Sustainability, MDPI, vol. 13(4), pages 1-20, February.
    22. Feng Ming Tsai & Tat-Dat Bui, 2021. "Impact of word of mouth via social media on consumer intention to purchase cruise travel products," Maritime Policy & Management, Taylor & Francis Journals, vol. 48(2), pages 167-183, February.
    23. Sharma, Varinder M. & Klein, Andreas, 2020. "Consumer perceived value, involvement, trust, susceptibility to interpersonal influence, and intention to participate in online group buying," Journal of Retailing and Consumer Services, Elsevier, vol. 52(C).
    24. Kang, Kai & Lu, Jinxuan & Guo, Lingyun & Li, Wenlu, 2021. "The dynamic effect of interactivity on customer engagement behavior through tie strength: Evidence from live streaming commerce platforms," International Journal of Information Management, Elsevier, vol. 56(C).
    25. Molinillo, Sebastian & Aguilar-Illescas, Rocío & Anaya-Sánchez, Rafael & Liébana-Cabanillas, Francisco, 2021. "Social commerce website design, perceived value and loyalty behavior intentions: The moderating roles of gender, age and frequency of use," Journal of Retailing and Consumer Services, Elsevier, vol. 63(C).
    26. Qiulai Su & Fei Zhou & Yenchun Jim Wu, 2020. "Using Virtual Gifts on Live Streaming Platforms as a Sustainable Strategy to Stimulate Consumers’ Green Purchase Intention," Sustainability, MDPI, vol. 12(9), pages 1-15, May.
    27. Md. Alamgir Hossain & Minho Kim, 2020. "A Comprehensive Study on Social Commerce in Social Networking Sites," SAGE Open, , vol. 10(2), pages 21582440209, June.
    28. Prince Clement Addo & Jiaming Fang & Andy Ohemeng Asare & Nora Bakabbey Kulbo, 2021. "Customer engagement and purchase intention in live-streaming digital marketing platforms," The Service Industries Journal, Taylor & Francis Journals, vol. 41(11-12), pages 767-786, September.
    29. Muhammad Usman Riaz & Luo Xiao Guang & Maria Zafar & Fakhar Shahzad & Muhammad Shahbaz & Majid Lateef, 2021. "Consumers’ purchase intention and decision-making process through social networking sites: a social commerce construct," Behaviour and Information Technology, Taylor & Francis Journals, vol. 40(1), pages 99-115, January.
    30. Hu, Xi & Huang, Qian & Zhong, Xuepan & Davison, Robert M. & Zhao, Dingtao, 2016. "The influence of peer characteristics and technical features of a social shopping website on a consumer’s purchase intention," International Journal of Information Management, Elsevier, vol. 36(6), pages 1218-1230.
    31. Mohd Suki, Norazah & Mohd Suki, Norbayah, 2017. "Modeling the determinants of consumers' attitudes toward online group buying: Do risks and trusts matters?," Journal of Retailing and Consumer Services, Elsevier, vol. 36(C), pages 180-188.
    32. Wang, Yichuan & Yu, Chiahui, 2017. "Social interaction-based consumer decision-making model in social commerce: The role of word of mouth and observational learning," International Journal of Information Management, Elsevier, vol. 37(3), pages 179-189.
    33. Guo, Yuanyuan & Zhang, Kexin & Wang, Chaoyou, 2022. "Way to success: Understanding top streamer's popularity and influence from the perspective of source characteristics," Journal of Retailing and Consumer Services, Elsevier, vol. 64(C).
    34. Hajli, Nick & Sims, Julian & Zadeh, Arash H. & Richard, Marie-Odile, 2017. "A social commerce investigation of the role of trust in a social networking site on purchase intentions," Journal of Business Research, Elsevier, vol. 71(C), pages 133-141.
    35. Jian Wang & Fakhar Shahzad & Zeeshan Ahmad & Muhammad Abdullah & Nadir Munir Hassan, 2022. "Trust and Consumers’ Purchase Intention in a Social Commerce Platform: A Meta-Analytic Approach," SAGE Open, , vol. 12(2), pages 21582440221, April.
    36. Zhao, Yang & Ni, Qi & Zhou, Ruoxin, 2018. "What factors influence the mobile health service adoption? A meta-analysis and the moderating role of age," International Journal of Information Management, Elsevier, vol. 43(C), pages 342-350.
    37. Fu, Senhui & Yan, Qing & Feng, Guangchao Charles, 2018. "Who will attract you? Similarity effect among users on online purchase intention of movie tickets in the social shopping context," International Journal of Information Management, Elsevier, vol. 40(C), pages 88-102.
    38. Wang, Xuequn & Wang, Yichuan & Lin, Xiaolin & Abdullat, Amjad, 2021. "The dual concept of consumer value in social media brand community: A trust transfer perspective," International Journal of Information Management, Elsevier, vol. 59(C).
    39. Sarkar, Subhro & Chauhan, Sumedha & Khare, Arpita, 2020. "A meta-analysis of antecedents and consequences of trust in mobile commerce," International Journal of Information Management, Elsevier, vol. 50(C), pages 286-301.
    40. Bai, Yan & Yao, Zhong & Dou, Yi-Fan, 2015. "Effect of social commerce factors on user purchase behavior: An empirical investigation from renren.com," International Journal of Information Management, Elsevier, vol. 35(5), pages 538-550.
    41. Jiang, Cuiqing & Rashid, Rao Muhammad & Wang, Jianfei, 2019. "Investigating the role of social presence dimensions and information support on consumers’ trust and shopping intentions," Journal of Retailing and Consumer Services, Elsevier, vol. 51(C), pages 263-270.
    42. Umair Akram & Peng Hui & Muhammad Kaleem Khan & Chen Yan & Zubair Akram, 2018. "Factors Affecting Online Impulse Buying: Evidence from Chinese Social Commerce Environment," Sustainability, MDPI, vol. 10(2), pages 1-28, January.
    43. Islam, Tahir & Pitafi, Abdul Hameed & Akhtar, Naeem & Xiaobei, Liang, 2021. "Determinants of purchase luxury counterfeit products in social commerce: The mediating role of compulsive internet use," Journal of Retailing and Consumer Services, Elsevier, vol. 62(C).
    44. Zhou, Min & Huang, Jinlong & Wu, Kexin & Huang, Xin & Kong, Nan & Campy, Kathryn S., 2021. "Characterizing Chinese consumers’ intention to use live e-commerce shopping," Technology in Society, Elsevier, vol. 67(C).
    45. Shanmugam, Mohana & Sun, Shiwei & Amidi, Asra & Khani, Farzad & Khani, Fariborz, 2016. "The applications of social commerce constructs," International Journal of Information Management, Elsevier, vol. 36(3), pages 425-432.
    46. Zhao, Jing-Di & Huang, Jin-Song & Su, Song, 2019. "The effects of trust on consumers’ continuous purchase intentions in C2C social commerce: A trust transfer perspective," Journal of Retailing and Consumer Services, Elsevier, vol. 50(C), pages 42-49.
    47. Hajli, M. Nick, 2014. "The role of social support on relationship quality and social commerce," Technological Forecasting and Social Change, Elsevier, vol. 87(C), pages 17-27.
    48. Lee, Jieun & Hong, Ilyoo B., 2016. "Predicting positive user responses to social media advertising: The roles of emotional appeal, informativeness, and creativity," International Journal of Information Management, Elsevier, vol. 36(3), pages 360-373.
    49. Cheng, Hsiu-Hua & Huang, Shih-Wei, 2013. "Exploring antecedents and consequence of online group-buying intention: An extended perspective on theory of planned behavior," International Journal of Information Management, Elsevier, vol. 33(1), pages 185-198.
    50. Kee-Young Kwahk & Byoungsoo Kim, 2017. "Effects of social media on consumers’ purchase decisions: evidence from Taobao," Service Business, Springer;Pan-Pacific Business Association, vol. 11(4), pages 803-829, December.
    51. Dabbous, Amal & Barakat, Karine Aoun, 2020. "Bridging the online offline gap: Assessing the impact of brands’ social network content quality on brand awareness and purchase intention," Journal of Retailing and Consumer Services, Elsevier, vol. 53(C).
    52. Akram, Umair & Junaid, Muhammad & Zafar, Abaid Ullah & Li, Zhiwen & Fan, Mingyue, 2021. "Online purchase intention in Chinese social commerce platforms: Being emotional or rational?," Journal of Retailing and Consumer Services, Elsevier, vol. 63(C).
    53. Xiang, Li & Zheng, Xiabing & Lee, Matthew K.O. & Zhao, Dingtao, 2016. "Exploring consumers’ impulse buying behavior on social commerce platform: The role of parasocial interaction," International Journal of Information Management, Elsevier, vol. 36(3), pages 333-347.
    54. Rao Muhammad Rashid & Qurat ul Ain Rashid & Abdul Hameed Pitafi, 2020. "Examining the Role of Social Factors and Mooring Effects as Moderators on Consumers’ Shopping Intentions in Social Commerce Environments," SAGE Open, , vol. 10(3), pages 21582440209, August.
    55. Nisar, Tahir M. & Prabhakar, Guru, 2017. "What factors determine e-satisfaction and consumer spending in e-commerce retailing?," Journal of Retailing and Consumer Services, Elsevier, vol. 39(C), pages 135-144.
    56. Ming-Yan Wang & Peng-Zhu Zhang & Cheng-Yang Zhou & Neng-Ye Lai, 2019. "Effect of Emotion, Expectation, and Privacy on Purchase Intention in WeChat Health Product Consumption: The Mediating Role of Trust," IJERPH, MDPI, vol. 16(20), pages 1-19, October.
    57. Fan-Yun Pai & Tsu-Ming Yeh, 2014. "The effects of information sharing and interactivity on the intention to use social networking websites," Quality & Quantity: International Journal of Methodology, Springer, vol. 48(4), pages 2191-2207, July.
    58. Jian Wang & Guoyi Xiu & Fakhar Shahzad, 2019. "Exploring the Determinants of Online Health Information-Seeking Behavior Using a Meta-Analytic Approach," Sustainability, MDPI, vol. 11(17), pages 1-13, August.
    59. Hsu, Meng-Hsiang & Chang, Chun-Ming & Chuang, Li-Wen, 2015. "Understanding the determinants of online repeat purchase intention and moderating role of habit: The case of online group-buying in Taiwan," International Journal of Information Management, Elsevier, vol. 35(1), pages 45-56.
    60. M. Awais Shakir Goraya & Zhu Jing & Mahmud Akhter Shareef & Muhammad Imran & Aneela Malik & M. Shakaib Akram, 2021. "An investigation of the drivers of social commerce and e-word-of-mouth intentions: Elucidating the role of social commerce in E-business," Electronic Markets, Springer;IIM University of St. Gallen, vol. 31(1), pages 181-195, March.
    61. Xu-Priour, Dong-Ling & Truong, Yann & Klink, Richard R., 2014. "The effects of collectivism and polychronic time orientation on online social interaction and shopping behavior: A comparative study between China and France," Technological Forecasting and Social Change, Elsevier, vol. 88(C), pages 265-275.
    Full references (including those not matched with items on IDEAS)

    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. Jian Wang & Fakhar Shahzad & Zeeshan Ahmad & Muhammad Abdullah & Nadir Munir Hassan, 2022. "Trust and Consumers’ Purchase Intention in a Social Commerce Platform: A Meta-Analytic Approach," SAGE Open, , vol. 12(2), pages 21582440221, April.
    2. Agag, Gomaa & Eid, Riyad & Chaib Lababdi, Houyem & Abdelwahab, Mohamed & Aboul-Dahab, Sameh & Abdo, Said Shabban, 2024. "Understanding the impact of national culture differences on customers’ online social shopping behaviours," Journal of Retailing and Consumer Services, Elsevier, vol. 79(C).
    3. Yogesh K Dwivedi & Elvira Ismagilova & Prianka Sarker & Anand Jeyaraj & Yassine Jadil & Laurie Hughes, 2023. "A Meta-Analytic Structural Equation Model for Understanding Social Commerce Adoption," Information Systems Frontiers, Springer, vol. 25(4), pages 1421-1437, August.
    4. Wu, Wei & Wang, Sihang & Ding, Guanqi & Mo, Jinfei, 2023. "Elucidating trust-building sources in social shopping: A consumer cognitive and emotional trust perspective," Journal of Retailing and Consumer Services, Elsevier, vol. 71(C).
    5. Laradi, Sofiane & Alrawad, Mahmaod & Lutfi, Abdalwali & Agag, Gomaa, 2024. "Understanding factors affecting social commerce purchase behavior: A longitudinal perspective," Journal of Retailing and Consumer Services, Elsevier, vol. 78(C).
    6. Meng Tao & Faizan Alam & Eva Lahuerta-Otero & Chen Mengyuan, 2024. "Get Ready to Buy With Me: The Effect of Social Presence Interaction and Social Commerce Intention on S-commerce Live Streaming," SAGE Open, , vol. 14(1), pages 21582440241, March.
    7. Jinjie Li & Jiayin Qi & Lianren Wu & Nan Shi & Xu Li & Yuxin Zhang & Yinyin Zheng, 2021. "The Continued Use of Social Commerce Platforms and Psychological Anxiety—The Roles of Influencers, Informational Incentives and FoMO," IJERPH, MDPI, vol. 18(22), pages 1-19, November.
    8. Li, Nianlin & Xuan, Changchun & Chen, Rui, 2024. "Different roles of two kinds of digital coexistence: The impact of social presence on consumers' purchase intention in the live streaming shopping context," Journal of Retailing and Consumer Services, Elsevier, vol. 80(C).
    9. Xu, Xiao-Yu & Gao, Ya-Xuan & Jia, Qing-Dan, 2023. "The role of social commerce for enhancing consumers’ involvement in the cross-border product: Evidence from SEM and ANN based on MOA framework," Journal of Retailing and Consumer Services, Elsevier, vol. 71(C).
    10. Dong, Xueyan & Wang, Tienan, 2018. "Social tie formation in Chinese online social commerce: The role of IT affordances," International Journal of Information Management, Elsevier, vol. 42(C), pages 49-64.
    11. Kareem M. Selem & Muhammad Haroon Shoukat & Syed Asim Shah & Marianny Jessica Brito Silva, 2023. "The dual effect of digital communication reinforcement drivers on purchase intention in the social commerce environment," Palgrave Communications, Palgrave Macmillan, vol. 10(1), pages 1-12, December.
    12. Mustafa Kavacik & Kevser Çinar & Saadet Zafer Kavacik, 2023. "Visual Mapping of Social Commerce Articles on WoS Database Between 1995 and 2023," SAGE Open, , vol. 13(4), pages 21582440231, December.
    13. Dawei Liu & Jinyang Yu, 2024. "Impact of perceived diagnosticity on live streams and consumer purchase intention: streamer type, product type, and brand awareness as moderators," Information Technology and Management, Springer, vol. 25(3), pages 219-232, September.
    14. Mou, Jian & Benyoucef, Morad, 2021. "Consumer behavior in social commerce: Results from a meta-analysis," Technological Forecasting and Social Change, Elsevier, vol. 167(C).
    15. Han, Min Chung, 2023. "Checkout button and online consumer impulse-buying behavior in social commerce: A trust transfer perspective," Journal of Retailing and Consumer Services, Elsevier, vol. 74(C).
    16. Isaac Kofi Mensah & Guohua Zeng & Chuanyong Luo, 2023. "Determinants of Social Commerce Purchase and Recommendation Intentions Within the Context of Swift Guanxi Among Chinese College Students," SAGE Open, , vol. 13(2), pages 21582440231, June.
    17. Alzaidi, Maram Saeed & Agag, Gomaa, 2022. "The role of trust and privacy concerns in using social media for e-retail services: The moderating role of COVID-19," Journal of Retailing and Consumer Services, Elsevier, vol. 68(C).
    18. Aladwani, Adel M., 2018. "A quality-facilitated socialization model of social commerce decisions," International Journal of Information Management, Elsevier, vol. 40(C), pages 1-7.
    19. Lu, Hsiao-Han & Chen, Ching-Fu & Tai, Yi-Wen, 2024. "Exploring the roles of vlogger characteristics and video attributes on followers’ value perceptions and behavioral intention," Journal of Retailing and Consumer Services, Elsevier, vol. 77(C).
    20. Busalim, Abdelsalam H. & Hussin, Ab Razak Che, 2016. "Understanding social commerce: A systematic literature review and directions for further research," International Journal of Information Management, Elsevier, vol. 36(6), pages 1075-1088.

    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:sae:sagope:v:14:y:2024:i:2:p:21582440241257591. 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: SAGE Publications (email available below). General contact details of provider: .

    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.