An increased openness is nowadays demanded from policy-makers as well as public authorities and services to allow public participation to enhance policy-making and innovation processes. Building on the open innovation paradigm the search is on for external ideas and knowledge. Within the commercial sector open innovation and collaboration with customers and users have long been proven to be useful ways to improve the innovation process. The development of the Web 2.0 has opened up interesting new ways to effectively tap the knowledge of a crowd of individuals of varying knowledge, heterogeneity and number. In recent years the crowdsourcing of ideas – based on open, online idea calls or competitions – has become a popular tool for the generation of external knowledge. The outcomes of such attempts in the commercial sector have already received quite some academic attention.
Currently we are witnessing a rapid increase in the number of local, national and international ‘citizensourcing’ initiatives. Especially local governments and municipalities try to use citizensourcing to increase citizen participation in public service innovation and to facilitate more participative policy-making, often referred to as policy-making 2.0. Despite the importance and the fast growing number of such ideation initiatives there is a lack of systematic research on this matter and little empirical evidence concerning the opportunities, limitations and effects of citizensourcing.
The pressure on such citizensourcing initiatives is high: On the one hand fresh ideas are desperately needed to deal with the major (financial, social or ecological) challenges of our time; on the other hand the development of the Web 2.0 put governments increasingly under pressure to open up, to be more transparent and to facilitate public participation. Bringing in large numbers of new and diverse ideas from a wide range of citizens could be an attractive way forward, if the crowdsourced ideas can actually be absorbed by the knowledge seeker for the desired purpose. Otherwise such attempts do not only fail to generate the wanted external ideas and knowledge, instead they could even lead to further political disenchantment if the citizens involved get the feeling, that their ideas and opinions are not being heard and accepted by the knowledge seeker.
To actually make use of external knowledge – such as the ideas generated via crowdsourcing initiatives – the knowledge seeker needs to possess the capacity to actually absorb it. Research has shown that the absorptive capacity of an organisation is an important prerequisite for organisational learning and knowledge utilisation. By looking at the absorption process the absorptive capacity construct therefore also provides an interesting starting point to assess the generation and utilisation of citizensourced knowledge.
The process of absorption is defined to involve the acquisition, assimilation, transformation and exploitation of external knowledge. The first two capabilities (i.e. the acquisition and assimilation of external knowledge) describe the potential absorptive capacity being the capability to identify and acquire as well as understand external knowledge. The latter two capabilities (i.e. the transformation and exploitation of external knowledge) describe the realised absorptive capacity being the ability to refine, develop and eventually utilise this external knowledge. Applying this to the process of citizensourcing, this leads to the following research questions:  Can citizensourcing be used to acquire new and comprehensible external ideas to facilitate policy making and public service innovation?  Can those citizensourced ideas be refined and developed in such a way that this new knowledge can actually be applied?
Answers to these questions were found as part of an exploratory case study on an award-winning citizensourcing initiative in the German city of Munich. Under the headline ‘ideas for digital Munich’ the initiative organised by the municipality collected 153 ideas and about 850 comments within a 7-week period in December 2010 und January 2011. It was one of the first initiatives of its kind in Germany.
Insights from interviews and preliminary qualitative data analysis indicate that citizensourcing can  be used to generate new and comprehensible ideas and  those ideas can be transformed into knowledge, which can be used for policy-making as well as innovation and development purposes. Only about 1 % of the generated ideas were discarded by the knowledge seeker. The remaining ideas were transformed and used in very different ways.
a) Policy-making 2.0: the content of the ideas was used as valuable input for a policy-making process namely the development of the city’s e-government roadmap. In addition the ideas and comments of the citizens were a useful source to support the public acceptance of this process.
b) Public participation in public service innovation: some entries offer very precise ideas and solutions for new or developed public services, which were directly be implemented, others serve as a starting point for further ideation and service innovation processes. In addition some ideas contain information for potential public participation via user innovation based on the allocation of open data.
Despite these promising first insights further research is needed to fully understand the opportunities, limitations and effects of citizensourcing initiatives. This means we need to develop a better understanding of how external knowledge is actually absorbed by the knowledge seeker to recognise the full potential of public participation and policy-making 2.0.