# Agreement Technologies for Coordination in Smart Cities
## 4 Discussion  
In this paper, we have argued that recent technological advances open up new possibilities for computers to support people's interactions in a variety of domains with high socioeconomic potential. In these domains, the choices and actions of a large number autonomous stakeholders need to be coordinated, and interactions can be regulated, by some sort of intelligent computing infrastructure, through institutions and institutional agents, or simply by providing information in an environment with a significant level of uncertainty. Many problems related to the vision of smart cities fall under this umbrella. While centrally designed systems may be a suitable choice to address certain challenges related to smart cities, others are unlikely to be dealt with satisfactorily, either because stakeholders are _unwilling_ to implement system recommendations that they do not understand and that they may not trust, or because it is _impossible_ to compute good global solutions based on the information provided by stakeholders, which can be insufficient or biased by their personal interests. While the former problem can be addressed by providing stakeholders with their own trusted software agent, which represents them and acts on their behalf, the latter requires coordination mechanisms that take into account the _autonomy_ of the stakeholders (and their software agents). Still, designing and implementing such coordination mechanisms in open systems is challenging, especially if the systems are large in scale, as in the case of most smart city applications. We argued that technologies from the AT sandbox are suitable for fostering coordination in such scenarios. To back this claim, we reported on a variety of real-world applications, ranging from truly open systems, where coordination among agents is achieved either though (economic) incentives or by offering relevant information, to more closed domains, where AT techniques are  
Figure 14: Average net income of taxi drivers and mediator in euros. The data are normalised to 1000 taxis serving 1000 customers. used to \"simulate\" interactions among autonomous agents, which may, for instance, take the shape of auctions or market equilibria. While in some of the applications the use of AT (market-based approaches, in particular) was a mere design choice, in other more open domains, their use enables the provision of new functionalities and services. In fact, a key lesson learnt from our work is that market-based coordination schemes can be successfully applied to quite different problems and domains, even though their particular shape needs to be carefully tailored and adapted based on the degree of autonomy of the stakeholders. In the applications outlined in Sections 3.3 and 3.4, the degree of autonomy of the different agents is low, as ambulance drivers, for instance, have to follow the assignments that they are given by the coordination mechanism. Evacuees in Section 3.2 do have a choice but, due to the specific characteristics of the emergency situation and the scarceness of adequate information, the suggestions of the system are likely to be followed. A similar \"take it or leave it\" situation is present in the taxi fleet coordination example of Section 3.5, but the stakeholders can make more informed decisions, so it is important that the incentives offered as part of the system proposal are such that taxi drivers can conclude that they are better off following the recommendations than not following them. Finally, within the case study related to networks of reservation-based intersections in Section 3.1, there are no explicit proposals for drivers to follow a particular route, but traffic assignment is achieved implicitly by coordinating the intersections' reserve prices. In addition, the auction protocol used at each reservation-based intersection needs to be such that the mechanism is resilient to attempts of strategic manipulation. A limitation of our approach is related to the level of scalability needed for a particular domain.