Papers by Mustafa YILDIRIM
Second-Leg Home Advantage No More? The Impact of Video Assistant Referee and No Away Goals Rule in Elite Soccer (with Mustafa Erhan Bilman)
Journal of Policy Modeling, 2025
Does hosting the return leg in two-legged soccer ties improve a team’s advancement chances, as so... more Does hosting the return leg in two-legged soccer ties improve a team’s advancement chances, as some contend, or is this perceived second-leg home advantage merely an illusion, as others argue? This question of competitive fairness is increasingly pertinent in today’s high-stakes soccer environment. While a definitive answer remains elusive, recent rule changes in European soccer, namely the introduction of the video assistant referee (VAR) system and the abolition of the away goals rule (AGR), have added new complexities. Analyzing 906 UEFA Champions League ties (2000/01–2023/24) via weighted logistic regression with robustness checks and team strength controls, we find that a modest second-leg home advantage appears only when AGR is in effect without VAR. Introducing VAR alongside AGR seemingly reverses that advantage, albeit lacking robustness, while neither rule alone nor both absent yields an order effect. Notably, VAR offsets the second-leg home advantage solely in AGR’s presence, while AGR creates that advantage solely in VAR’s absence. Although team quality remains the primary driver of success, these findings illustrate how seemingly innocuous regulatory shifts can redefine competitive fairness. Our results thus offer timely insights for policymakers aiming to design fair and strategically engaging formats in elite European soccer, particularly given the dearth of research on the subject.
New rules, new game? The effects of the away goals rule removal and video assistant referee adoption on game dynamics in UEFA Champions League ties (with Mustafa Erhan Bilman)
Journal of Policy Modeling, 2025
This study investigates the impact of two recent rule changes in European soccer: the abolition o... more This study investigates the impact of two recent rule changes in European soccer: the abolition of the away goals rule (AGR) and the introduction of the Video Assistant Referee (VAR) system. Specifically, it examines how these changes affect game dynamics, focusing on playing style indicators and disciplinary outcomes within the UEFA Champions League. We collect data on 1244 two-legged ties (2488 individual matches), spanning the seasons from the start of 2000/01 to the play-off stage of 2023/24. By analyzing the data at both the aggregate tie and individual leg levels and controlling for an extensive array of confounding variables, we challenge UEFA’s rationale for discontinuing the AGR. Contrary to UEFA’s justification for its removal, our findings reveal that the AGR promotes offensive rather than defensive play. Our findings regarding the VAR accord with the predominant view in the literature: less referee bias against away teams and increased aversion to risky tackles, hence, fewer disciplinary infractions. Given that the ties played under the AGR are found to be more competitive and thus more entertaining, our key policy implication is that UEFA should consider reinstating the AGR. Our results also suggest that the VAR should remain in place as it stimulates fairness and rule-abiding play.
When does division matter? Revisiting the optimal contest architecture
Economics Letters, 2023
We compare the aggregate effort between centralized and decentralized contests. Employing a relat... more We compare the aggregate effort between centralized and decentralized contests. Employing a relatively general setting that admits the ratio-form and additive-noise contests as special cases, we identify the population size elasticity of marginal winning probability as a key determinant of this comparison.
Bogazici Journal, 2019
There are two important but distinct literatures emphasizing the strategic values of debt financi... more There are two important but distinct literatures emphasizing the strategic values of debt financing and managerial delegation in oligopolistic markets. In this paper, I construct a unified model that allows firms to choose both. My main finding is that each firm views its debt and managerial delegation as substitute choices under quantity competition, and as complementary choices under price competition, regardless of products' being substitutes or complements.
Review of Economic Design, 2015
Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch ge... more Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may be saved and copied for your personal and scholarly purposes. You are not to copy documents for public or commercial purposes, to exhibit the documents publicly, to make them publicly available on the internet, or to distribute or otherwise use the documents in public. If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence.
There are two important but distinct literatures emphasizing the strategic values of debt financi... more There are two important but distinct literatures emphasizing the strategic values of debt financing and managerial delegation in oligopolistic markets. In this paper, I construct a unified model that allows firms to choose both. My main finding is that each firm views its debt and managerial delegation as substitute choices under quantity competition, and as complementary choices under price competition, regardless of products’ being substitutes or complements.
Terörizmin Hisse Senedi Piyasasındaki İşlem Adedi Üzerindeki Etkisi: Türkiye Örneği. Selçuk Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, 42, 142-153, 2019. (with Fatma KÜÇÜK).
"Optimal Team Size under Legislative Bargaining with Costly Recognition," Economics Letters, 177, pp. 81-84, 2019.
I investigate team formation in a legislative bargaining model in which both the surplus and reco... more I investigate team formation in a legislative bargaining model in which both the surplus and recognition are endogenous. I find that the optimal team size increases with stricter agreement rules and longer-sighted agents but remains too small from the social perspective. Moreover, the optimal size may not exhaust increasing returns to scale.
"Legislative Bargaining with a Stochastic Surplus and Costly Recognition," Economics Letters, 163, pp. 102-105, 2018.
Merging Eraslan and Merlo (2002) and Yildirim (2007), I examine legislative bargaining with a sto... more Merging Eraslan and Merlo (2002) and Yildirim (2007), I examine legislative bargaining with a stochastic surplus and costly recognition. With symmetric agents, I show that (1) the symmetric stationary payoff is unique under a well-known hazard rate condition; (2) the agreement is sooner than that without costly recognition for all voting rules; and (3) the inefficiency in the timing of the agreement increases with the number of agents and contestability of recognition but decreases with the inclusiveness of the voting rule.
"Pre-contest Communication Incentives," The B.E. Journal of Theoretical Economics, 18(1), 2018.
To demonstrate resolution and psychological strength, players often engage in pre-contest communi... more To demonstrate resolution and psychological strength, players often engage in pre-contest communication by publicly stating their desire to win an upcoming contest. Existing explanations for this phenomenon revolve around incomplete information and signaling. In this paper, I offer a complementary explanation that does not rely on signaling. Within a complete information setup, I show that when communication involves not only an audience cost, e.g., a reputation loss, in case of a false statement (as assumed in the literature) but also an audience reward, e.g., a credibility gain, in case of a true statement, players may have an incentive for pre-contest communication.
This paper investigates the impact of terrorism that took place within Turkish borders on the Tur... more This paper investigates the impact of terrorism that took place within Turkish borders on the Turkish stock market by utilizing the daily time series of terror attacks and the benchmark stock index between 2000 and 2015. The terror data taken from the Global Terrorism Database distinguishes itself in several aspects, including location, attack types, the number of attacks, the number of victims killed, and the number of victims injured. It is shown that the stock market became desensitized to terror attacks over time. The sensitivity that is observed for the period of 2000-2004 is lost for the remaining period of 2004-2015. The sensitivity period includes the 2001 financial crisis of Turkey after which various financial reforms were implemented. Hence, the lost sensitivity over the 2004-2015 period is considered to be associated with the changing state of the financial system. Moreover, it is found that the location of an attack is unimportant for the stock market. However, when attacks are classified into types based on tactics used during the attack, it is shown that the stock market is negatively sensitive to terrorism only when the attack type is facilities/infrastructure. Since the conclusions are based on Turkey, they might have broader implications for developing countries.
We propose a political theory for the slow adoption of technology in sports and other contests. W... more We propose a political theory for the slow adoption of technology in sports and other contests. We investigate players' preferences for new technology that improves contest accuracy. Modeling accuracy as the elasticity of production in a standard Tullock contest, we show that players may dislike accuracy if heterogeneity among them is: (1) sufficiently low; (2) moderate when the initial accuracy is low; or (3) high when the initial accuracy is high. We apply our results to the recent adoption of goal-line technology by major European soccer leagues.
"Home vs. Away Team Advantage in Two-Legged Competitions"
In team sports such as soccer, elimination contests between two teams often arise in the form of ... more In team sports such as soccer, elimination contests between two teams often arise in the form of two-legged tie games, with each team as the home team in one leg. It has been argued that teams having the second leg at home have an advantage over their rivals. Utilizing a two-stage tournament model, I show that, contrary to popular belief, the outcome is neutral regarding the order of the hosting of games.
Talks by Mustafa YILDIRIM
"All İzmir Economics Workshop - II," Ege University, Turkey, 2017.
"Weekly Microeconomics Seminars," Bilkent University, Turkey, 2015.
"Weekly Economics Seminars," Ege University, Turkey, 2014.
"Borsa Istanbul - ITU Economics Department Seminar Series," Istanbul Technical University, Turkey, 2014.
"Economics Seminars," University of California, Irvine, USA, 2013.
"Economics Lunch Seminar," Stockholm School of Economics, Sweden, 2013.
Conference Presentations by Mustafa YILDIRIM
In sports competitions between a host and a visiting team, the host is believed to possess the so... more In sports competitions between a host and a visiting team, the host is believed to possess the so-called home advantage over its rival, thereby to stand enhanced chances of winning. The evidence for home advantage is compelling in virtually all sports that have been investigated, particularly in soccer (hereafter called football), where the magnitude of this advantage has been established to be more pronounced. While there is extensive literature on home advantage in football, few studies have contrasted its size across different levels of play and yielded conflicting results. Such comparison, however, may prove useful as a potential (dis)agreement in the value of hosting the game is likely to offer new insights into the causes of home advantage. With this motivation, the current work explores the possible variation in home advantage across the top two tiers of Turkish men's professional football leagues, namely, the Turkish Super and First Leagues, over the last two seasons (2017-18 and 2018-19). By interpreting home advantage as the increment in winning probability and the increase in the difference between the number of goals scored, the analysis employs the ordered probit and standard linear regression models, respectively. Since average crowd attendance is higher in the Super League than the First League, one would typically expect a higher home advantage in the former. The results match this intuition. Specifically, the ordered probit model that controls for ability gaps between the teams yields that a home venue improves the winning odds by 24.0% in the Super League, which is more than double the corresponding figure of 11.7% in the First League. Despite this marked contrast between them, however, in both leagues, the team that enjoys the most home advantage is the one which surpasses its opponent in the ability only by a small margin. In support of the more substantial advantage in the top-level league, the regression estimates demonstrate that the goal difference between the two teams of equal strength changes in the host team's favor by 0.906 in the Super League but by just 0.511 in the First League.
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Papers by Mustafa YILDIRIM
Talks by Mustafa YILDIRIM
Conference Presentations by Mustafa YILDIRIM