Pol. J. Sport Tourism 2022, 29(3), 36-42 36 DOI: 10.2478/pjst-2022-0019 Introduction According to Preuss [1], the mega sporting event’s lega- cy is considered to be “planned and unplanned, positive and negative, tangible and intangible structures created for and by a sport event, which remain longer than the event itself”. Unfor- tunately, neither this nor any other known defnition [2, 3] gives much clue as to how to measure the legacy of sporting events. This is mainly due to the potential size of the legacy, which may include, but is not limited to economy, culture, environment, social issues, urban regeneration, infrastructure changes, sport and image [4, 5, 6]. In the worldwide literature, infrastructural changes are supposed to be the most frequently mentioned types of mega sporting events’ (MSEs’) legacies [7, 8, 9, 10]. This development is usually called urban regeneration and is associated either with basic urban infrastructure within housing, sports facilities, transport development, etc. or advanced urban services such as smart city grids, improved safety and security features [3]. Once the Olympic Games are awarded to a host, structural changes are going to be made. These are not the least infrastructural pro- jects, which lie at the root of both internal drivers seen as all the requirements to stage the Olympic Games and external drivers that are of a political choice [11]. Infrastructural changes in the host area embrace urban regeneration both basic and advanced [3]. Simultaneously, the investment in infrastructure involves enormous capital demand, since nowadays the expenditures in- curred at the time of MSEs organisation mainly consist in infra- structural projects [12, 13]. The importance of infrastructural development is empha- sized by the International Olympic Committee (IOC) itself in the sense of taking some actions in order to ensure usefulness and utility of the infrastructure which fulfl the expectations of each host city’s population. That is why, in almost each bid report, special consideration is devoted to the maximum long- term use of the infrastructural projects in order to justify the massive expenditures incurred on that occasion [14]. For exam- ple, Sochi’s bid for the 2014 Winter Olympic Games (WOG) was based on the premiss that the Games would “modernise the area through creating substantial new transport, telecommu- nications and energy infrastructure as well as accommodation and sports facilities by creating new infrastructure in rail, road, telecommunications, energy and accommodation and through the construction of sports venues” [15]. Such an IOC approach does not mean, however, that infrastructural changes have only a positive impact on hosts, especially since it was not until 2012 Summer Olympic Games (SOG) that the organisers were seri- ously engaged in a legacy schedule for each infrastructure pro- ject [16, 17]. For many host cities, a well-known concept is the occurrence of “white elephants”, over-scaled sporting objects not at all adjusted to the needs of the area’s residents [18]. Measuring mega event legacies in general, but infrastruc- tural development in particular is considered to be a challenge. It is caused, among other things, by the longer duration of in- frastructural legacy in comparison to other types of legacy [15]. THE ECONOMIC LEGACY OF MEGA SPORTING EVENTS. THE IMPACT OF HOSTING EUROPEAN OLYMPIC GAMES ON GDP GROWTH THROUGH INFRASTRUCTURE DEVELOPMENT KRYSTIAN ZAWADZKI Gdansk University of Technology, Faculty of Management and Economics Mailing address: Krystian Zawadzki, Faculty of Management and Economics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk; tel.: +48 58 348 60 12; e-mail: kryzawad@pg.edu.pl Abstract Introduction. The positive legacy of the Olympics is often cited by the International Olympic Committee and national or- ganizers. Some scholars, however, question an uncritical approach to an exclusively positive economic legacy. The aim of this study is to evaluate the impact of hosting the Olympics on infrastructure development, with a potential impact on economic growth in the form of Gross Domestic Product (GDP) in three phases of seven Olympic Games organised in Europe in recent years. Material and methods. The effect of a particular Olympic period on the GDP was analysed using a difference-in-differ- ence technique in which the difference between each of the analysed seven host countries’ GDPs and those of a reference set of countries was obtained. Each time, as part of the observation, an event time period was distinguished covering all three phases of the event: the preparatory phase, the event phase and the post-event phase. Results. For the Winter Olympic Games, no statistically signifcant positive results are observed in the long term, which may indicate a very limited importance of the economic legacy of these events for potential host countries. In the case of Summer Olympic Games, the positive impact of the organization of these events in the post-event phase is noticeable. Conclusions. The obtained results confrm the ambiguous impact of Olympic Games on the hosts’ economies and are in line with the attitude of many scholars to an uncritical approach to the only positive legacy of these events. Key words: GDP, economic legacy, infrastructure, Olympic Games Original research papers