Web Appendix

Process used for identifying articles included in the literature review

We started in Step 1 with a keyword search in major databases, including ABI/INFORMS, Proquest, and Business Source Complete (EBSCO) to arrive at an initial pool of studies. Table A1 provides the details and criteria for our article search and selection. Regarding the keywords used in the literature search, similar to other CP review papers (e.g., Chang and Taylor 2016; Mustak et al. 2016; Ranjan and Reed 2016), we used “customer participation,” “customer coproduction,” and “customer cocreation” as the keywords appearing in the “document title” and limited our search to “peer-reviewed journals.”

Table A1. Article selection criteria for literature review

Criterion / Details
Step 1: Electronic search
Databases searched / ABI/INFORMS, Proquest, and Business Source Complete
Keywords used / “Customer participation,” “customer coproduction,” “customer cocreation” in the “document title”;
“Coproduction” and “cocreation” in the “document title” without “customer” as a prefix and “marketing,” “business,” or “service” in the “publication title”
Step 2: Manual search
Objective / To find additional articles that were not identified through the keyword search in the major databases.
Journals considered / A manual search in the following journals for articles published from 2000 to 2016: Journal of Marketing, Journal of Marketing Research, Journal of Consumer Research, Marketing Science, Journal of Service Research, Journal of the Academy of Marketing Science, Journal of Retailing, Journal of Business Research, Journal of Service Management, Journal of Services Marketing, Management Science
Reference checked / References in the articles identified were checked to obtain overlooked articles.
Step 3: Initial screening
Publication status / Only published or forthcoming peer-reviewed articles were considered; commentaries, case studies, book reviews, and working papers were not included.
Type of articles / When creating Table 1 and collecting empirical evidence, only empirical articles were included; conceptual articles, theory papers, and managerial pieces were not included.
Excluding irrelevant articles / Articles that used related keywords but were not relevant to our study were excluded.
Step 4: Refining the pool by substantive content
Content focus / Focus was on research work related to CP in service production and delivery, with particular attention to participation behaviors and activities.
Context focus / Based on the tradition in CP literature in services, articles were limited to the business-to-consumer domain, and only a few articles in the B2B domain were retained if they provide particular insights into different types of CP.
Domain focus / The massive literature on CE or CI is not included unless the studies have CP-related keywords in the document title and specify the type of customer input examined.

Note: CP = Customer participation; CE = Customer engagement; CI = Customer innovation

In Step 2, we used “coproduction” and “cocreation” in the “document title” without “customer” as a prefix; as the search returned several hundreds of entries, many of which were not relevant, we further refined our search by using “coproduction” and “cocreation”[1] in the “document title” and “marketing,” “business,” or “service” in the “publication title,” which returned a more focused and manageable number of articles. In Step 3, we supplemented the electronic searches with manual searches of articles published in major journals (see Table A1 for the journal list) between 2000 and 2016 (a time frame when the majority of CP research articles have appeared). In Step 4, we examined the references of the already identified articles to find overlooked studies. Steps 3 and 4 helped identify additional articles that were left out by the electronic search because the article title did not use CP-related keywords.

The initial examination of the identified publications indicated that there were redundant entries, and indeed many did not relate to our study or the concept of CP, even broadly defined. We examined the gathered evidence to further screen the articles. First, we only included peer-reviewed journal articles (published and forthcoming) while avoiding commentaries, case studies, book reviews, and working papers. Second, with the objective to compile empirical evidence of CP research, we did not include conceptual articles[2], theory papers, and managerial pieces (e.g., Harvard Business Review, Sloan Management Review). Third, we exclude articles that, despite using related keywords, were not relevant to our study (e.g., “Customer fee and participation in breast-cancer screening” published in a medical journal).

With this more refined pool of articles, we further followed Booth et al. (2012) to retain studies that were most relevant to the particular focus and scope of our research. We read the abstract of each article in the pool, filtering each against three criteria. First, we assessed the pertinence of the research work to the concept of CP in service production and delivery, paying particular attention to whether the study provided information about CP behaviors and activities. Second, to anchor us in the main body of the CP research stream, we limited our focus to the business-to-consumer domain and retained only a few articles (e.g., Fang 2008; Fang et al. 2008; Fang et al. 2015) in the B2B domain[3] if they provide particular insights into different types of CP. Third, we did not include the massive literature on customer engagement or customer innovation unless the studies had CP-related keywords in the document title and specified the type of customer input examined. (See our discussion in the main text on how we define the respective domains of CP, customer engagement, and customer innovation, and how our collection of articles is related to our proposed conceptualization.)

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[1] We also used “participation” as the keyword appearing in the document title without “customer” as a prefix, which returned thousands of entries, the majority of which were not relevant. Following Mustak et al. (2016), who faced the same issue in their literature search, we refined our search to make it more manageable (e.g., using “customer participation” as the keyword instead, using manual search and reference check to find overlooked articles).

[2] Although conceptual articles are not included in Table 1, they were included in our discussion of the concepts in the manuscript.

[3] We decided not to include B2B literature because the traditional channel and innovation research includes extensive research on a focal firm’s relationship with upstream supplier firms and downstream firms (e.g., wholesalers, retailers). Technically, all these relationships involve the customer; however, such B2B collaborations have not been the focus of existing CP research in the services domain. Thus, we follow the same approach and do not consider these B2B interactions the focus of our research.