# Costs and Benefits of Autonomous Shipping--A Literature Review
## 4 Discussion  
The conducted literature analysis was based on the use of one database--Google Scholar. The query used in the study was formulated generally, with the simultaneous attempt to exclude issues related to other scientific disciplines. However, there were many articles in the dataset concerning both medical and social sciences, which is due to the polysemy phenomenon. Moreover, the limitation of the study was the utilization of different words to describe the same issues by authors of the articles than those used in the query. Due to the above-mentioned challenges, some of the relevant articles could have been omitted.  
The herein performed literature review of the economic aspects of autonomous ships presents that much effort has been put into defining costs associated with the construction and operations of prospective autonomous ships, as well as developing relevant economic models for the aspects of the operation of the single ships as well as fleet of autonomous ships. However, there remain uncertainties regarding the costs, resulting mainly from the immaturity of the technology and various concepts of prospective ship and fleet operations. However, only after the introduction of autonomous ships into the shipping industry CAPEX and OPEX parameters can be determined.  
The business models play a significant role in evaluating innovative transport projects. It is generally acknowledged that autonomous ships can bring about direct economic advantages. However, apart from direct gains, there are also non-trivial ones. It shall be noted that the propulsion of the ship in most cases is said to be environmentally-friendly. However, the benefits from the reduced emissions of NOx and CO2 are not monetized within the existing models, while these issues gain ever-increasing attention [62; 63; 64]. Similarly, the costs related to safeguarding the cyber security [65; 66] remains an open question, as well as contingency operations, or any other safety critical area of conventional shipping that presently requires direct intervention of humans in case of failure. All these directly affect the costs of insurance of prospective autonomous ships, about which the authors of the reviewed documents remained silent.  
Another aspect is the economy of the scale. Meanwhile, the size of the fleet from the shipowner's point of view as the most favourable in cost-efficiency terms was not estimated for cases other than vessel platooning. Neither was the issue of how insurance rates would be affected by potentially different risk levels of autonomous ship operations [50]. Meanwhile, these account for as much as 1% of total operational costs of traditional vessels [67].  
Taking into account the data presented in the previously mentioned documents, we can assume that preparing a detailed economic model concerning the cost breakdown related to the operation of the autonomous vessel fleet would allow for a determination of the directions of further development of autonomous shipping aimed at reaping from the implemented solutions. Preparing a general business model may become challenging regarding the differences in characteristics and market conditions of the areas where autonomous shipping could be implemented. It would be essential to focus on case studies concerning economic feasibility for introducing the specific autonomous shipping line or shipping connection [68].  
The costs of potential accidents that the ship may be involved in is not accounted for. However, it is claimed that the prospective autonomous ships may be less likely accident-prone than the conventional ones [50].