S ince the inauguration of information systems research (ISR) two decades ago, the information systems (IS) field's attention has moved beyond administrative systems and individual tools. Millions of users log onto Facebook, download iPhone applications, and use mobile services to create decentralized work organizations. Understanding these new dynamics will necessitate the field paying attention to digital infrastructures as a category of IT artifacts. A state-of-the-art review of the literature reveals a growing interest in digital infrastructures but also confirms that the field has yet to put infrastructure at the centre of its research endeavor. To assist this shift we propose three new directions for IS research: (1) theories of the nature of digital infrastructure as a separate type of IT artifact, sui generis; (2) digital infrastructures as relational constructs shaping all traditional IS research areas; (3) paradoxes of change and control as salient IS phenomena. We conclude with suggestions for how to study longitudinal, large-scale sociotechnical phenomena while striving to remain attentive to the limitations of the traditional categories that have guided IS research.

As digital platforms are transforming almost every industry today, they are slowly finding their way into the mainstream information systems (ISs) literature. Digital platforms are a challenging research object because of their distributed nature and intertwinement with institutions, markets and technologies. New research challenges arise as a result of the exponentially growing scale of platform innovation, the increasing complexity of platform architectures and the spread of digital platforms to many different industries. This paper develops a research agenda for digital platforms research in IS. We recommend researchers seek to (1) advance conceptual clarity by providing clear definitions that specify the unit of analysis, degree of digitality and the sociotechnical nature of digital platforms; (2) define the proper scoping of digital platform concepts by studying platforms on different architectural levels and in different industry settings; and (3) advance methodological rigour by employing embedded case studies, longitudinal studies, design research, data-driven modelling and visualisation techniques. Considering current developments in the business domain, we suggest six questions for further research: (1) Are platforms here to stay? (2) How should platforms be designed? (3) How do digital platforms transform industries? (4) How can data-driven approaches inform digital platforms research? (5) How should researchers develop theory for digital platforms? and (6) How do digital platforms affect everyday life?

The digital age has seen the rise of service systems involving highly distributed, heterogeneous, and resourceintegrating actors whose relationships are governed by shared institutional logics, standards, and digital technology. The cocreation of service within these service systems takes place in the context of a paradoxical tension between the logic of generative and democratic innovations and the logic of infrastructural control. Boundary resources play a critical role in managing the tension as a firm that owns the infrastructure cansecure its control over the service system while independent firms can participate in the service system. In this study, we explore the evolution of boundary resources. Drawing on Pickering's (1993) and Barrett et al.'s (2012) conceptualizations of tuning, the paper seeks to forward our understanding of how heterogeneous actors engage in the tuning of boundary resources within Apple's iOS service system. We conduct an embedded case study of Apple's iOS service system with an in-depth analysis of 4,664 blog articles concerned with 30 boundary resources covering 6 distinct themes. Our analysis reveals that boundary resources of service systems enabled by digital technology are shaped and reshaped through distributed tuning, which involves cascading actions of accommodations and rejections of a network of heterogeneous actors and artifacts. Our study also shows the dualistic role of power in the distributed tuning process.Keywords: Service system innovation, mobile platform, ecosystem, digital infrastructure, boundary resource dynamics, tuning, sociomateriality, iOS Introduction 1Service is increasingly recognized as the foundation of activities and value creation in the global economy (Pine and Gilmore 1999;Vargo and Lusch 2004; Zuboff and Maxmin 2002). In combination with digital technology, we are witnessing fundamental shifts in business models, collaboration, and work practices in all levels of economic activity (Barrett and Davidson 2008). We define service broadly as "the application of specialized knowledge skills through deeds, processes, and performances for the benefit of customers" (Vargo and Lusch 2004, p. 2). In the service economy, value is cocreated by customers who appropriate service provided by the firm, integrating it with other resources, some of which are provided through market and others provided privately or publicly (Vargo and Lusch 2010). Therefore, service is 1 Michael Barrett, Elizabeth Davidson, Jaideep Prabhu, and Stephen L. Vargo were the accepting senior editors for this paper. The authors are listed in alphabetical order only.The appendix for this paper is located in the "Online Supplements" section of the MIS Quarterly's website (http://www.misq.org). Vargo et al. 2008). The notion of service system offers a general view of economic activities that can explain all types of economic transactions, ranging from the simple barter system of labor among individuals to a complex set of transactions in the global financial market (Vargo et al. 2008).S...

The stochastic behavior of agricultural commodity prices is investigated using observations of the term structures of futures prices over time. The continuous time dynamics of (log-) commodity prices are modeled as a sum of a deterministic seasonal component, a non-stationary statevariable, and a stationary state-variable. Futures prices are established by standard no-arbitrage arguments and the Kalman filter methodology is used to estimate the model parameters for corn futures, soybean futures, and wheat futures based on weekly data from the Chicago Board of Trade for the period 1972-1997. Furthermore, in a discussion of the estimated seasonal patterns in agricultural commodity prices, the paper provides empirical evidence on the theory of storage that predicts a negative relationship between stocks of inventory and convenience yields; in particular, convenience yields used in this analysis are extracted using the Kalman filter.

Digital platforms confer competitive advantage through superior architectural configurations. There is however still a dearth of research that sheds light on the competitive attributes which define platform competition from an architectural standpoint. To disentangle platform competition, we opted for the mobile payment market in the United Kingdom (UK) as our empirical setting. By conceptualizing digital platforms as layered modular architectures and embracing the theoretical lens of strategic groups, this study supplements prior research by deriving a taxonomy of platform profiles that is grounded on the strategic dimensions of value creation and value delivery architectures. We discover that mobile payment platforms could be delineated based on whether they are: (1) integrative or integratable on their value creation architecture; and (2) have direct, indirect, or open access on their value delivery architecture. The preceding attributes of value creation architecture and value delivery architecture aided us in identifying six profiles associated with mobile payment platforms, which in turn led us to advance three competitive strategies that could be pursued by digital platforms in network economies.