How open is this platform? The meaning and measurement of platform openness from the complementors' perspective

Software platforms' success largely depends on complementors' willingness to repeatedly invest their time and effort to the development of platform applications that attract users and increase the platform's installed base. But how can platform providers encourage desirable behaviours by complementors (i.e., application developers) in the absence of formal roles and hierarchical control structures? Although previous studies of software-based platforms have identified openness as critical instrument at the macro (i.e., platform) level and have provided initial attempts to measure the construct, no research has been dedicated to comprehensively conceptualize and operationalize platform openness at the micro level from the perspective of application developers. To go beyond these preliminary findings and to theorize about the nature and effects of platform openness as perceived by application developers, we develop a construct called perceived platform openness (PPO). Drawing on recently advanced scale development methodologies, we conceptualize PPO as a multidimensional construct and empirically validate it with important consequent variables linked to developers' continuous platform contributions. Empirical evidence from several rounds of qualitative and quantitative steps supports the conceptual validity of the construct and empirical relevance of the scale across different smartphone platform contexts (i.e., Apple iOS and Google Android). Researchers will benefit from the study's systematic and comprehensive conceptualization of PPO, how it is measured, and how it relates to critical application developer beliefs and attitudes. Platform managers may use our results to target the underlying facets of PPO most likely to contribute to the platform's long-term goals.