| 摘要: | 隨著社會變遷與科技的進步，休閒娛樂漸漸的在現代人的生活中扮演愈來愈重要的角色，其中職業運動更是搭上這股浪潮，包括北美四大職業運動聯盟以及歐洲的職業足球聯盟等，在世界各地都迅速累積了為數可觀的球迷。由於球迷的熱情，許多關於職業球隊與球員的各項數據都被詳細的紀錄下來，而這些數據更成為經濟學家用來驗證經濟理論的良好素材。在本論文中，我使用了美國職棒大聯盟(Major League Baseball, MLB)的投打契約和薪資資訊、球員們場上攻守數據以及美國職業籃球聯盟(National Basketball Association, NBA)的球隊經營資料，分別實證研究了包括勞動經濟學、契約理論和企業經營管理等領域的三個議題。實證結果分別描述如下：
在第二章中，為了研究勞動經濟學上關心的一個議題—勞動者慣用手和其所獲薪資的關連，我蒐集了2002至2011球季328位MLB投手的薪資以及場上攻守數據的縱橫資料(panel data)，實證研究投手薪資議定時，左撇子在互動性運動中所享有的策略優勢(tactical advantages)是否會為左投手帶來相較於右投手薪資上的優勢。實證結果發現，在其他情況不變之下，左投手相較於右投手並不享有任何的薪資貼水。基於棒球運動的特性，可能的原因是：左投手的優勢僅僅出現在面對左打者時，面對右打者卻反而處於不利，以MLB右打者為多數的狀況下，左投手的左手優勢並不顯著，因此策略優勢並無法為左投手帶來任何薪資上的好處。此外，若更進一步依照任務將投手分成先發投手、中繼投手與終結者等三類，分析發現各類型投手中，左投手和右投手的薪資仍無顯著差異，顯示投手的薪資主要取決於球員的場上表現，和其慣用手並無關連，這樣的結果和大部分球迷的猜測並不相同。
第三章則將研究重點轉向不確定性和人力資本專屬性投資之間的關係。在契約理論中，不確定性如何影響契約長短並無定論，且人力資本專屬性投資在個人勞動契約中的角色缺少實證研究的支持，因此我使用2003至2011的MLB打者契約資料，以打者場上數據中無法被球隊預測的部分作為不確定性的代理變數，發現不確定性和契約長度呈現正向的關係，支持風險均攤假說(risk-sharing hypothesis)，顯示勞動契約符合其設計的初衷，確實能夠幫助勞動者分攤風險。另外，捕手相較於其他守備位置球員來說，投入了更多的人力資本專屬性投資，所以我選擇以捕手做為人力資本專屬性投資的代理變數，實證結果也發現，為了避免投機行為的發生，投入愈多人力資本專屬性投資的勞動者，也將獲得較長的契約長度作為保障。
最後，第四章則根據職業球隊經營的特性，估計NBA球隊經營效率，並針對實證結果提供經營建議。一般職業球隊的經營可分成兩個階段，第一階段將球員薪資轉換成球員的攻守數據，第二階段則是將球員的攻守數據進一步轉換成球隊勝利與球隊收入。在此生產結構之下，我利用兩階段數據包絡分析分解法(the additive efficiency decomposition in two-stage DEA)，將整體球隊經營效率分解成第一階段的薪資效率以及第二階段的場上效率，同時也內生解出這兩階段效率值各別佔整體效率值的比重。實證結果發現，一般NBA球隊第一階段的薪資效率高於第二階段的場上效率，且整體經營效率中，第一階段的效率比重遠遠高於第二階段所佔的效率比重，因此球隊經營者如果想提高整體經營效率，應該更用心於改善第一階段的薪資效率，在給予球員薪資時更加謹慎。
;With the society transformation and technology progress, the importance of leisure activities has become greater in today’s modern society. Among those leisure activities, professional sports have followed this trend and accumulate many fans around the globe. Thanks to fans’ enthusiasm, many detailed statistics of professional teams and players are recorded. Furthermore, these statistics have also been used by economists to examine many economic theories. In this dissertation, I adopt data from professional sports to study three issues in labor economics, contract theory, and management of enterprises, respectively.
In chapter 2, I collect the panel data that consists of MLB pitchers’ salary information and their on-field performance from 2002 to 2011, in order to investigate an important issue in labor economics—the correlation between labor handedness and their salaries. According to my results, there are no salary differences between left-handed pitchers and right-handed pitchers. The possible reason is that, based on the characteristics of baseball, left-handed pitchers have advantages only when facing left-handed batters. Right-handed hitters, conversely, give disadvantages to these southpaws. Provided that majority of batters are right-handed in MLB, the tactical advantage enjoyed by left-handers in interactive sports is not significant for left-handed pitchers. Therefore, tactical advantages of left-handers cannot offer left-handed pitchers any salary premium. Moreover, when further separating pitchers into three types: starters, relievers, and closers, there is still no salary premium being discovered on left-handed pitchers within any types of pitchers. These results suggest that handedness does not matter to pitchers’ salaries. How many salaries a pitcher can obtain is mainly determined from his on-field performance.
In chapter 3, the focus is turned to examine how uncertainty and specific human capital affect the negotiated contract length. In the field of contract theory, there has been no consensus being reached on the relationship between uncertainty and contract duration. Moreover, there is no study investigating the effects of specific human investment on contract length. Therefore, I gather MLB batters’ contract information from 2003 to 2011 to conduct the research. Using the unobservable portion of batters’ on-field performance as a proxy for production uncertainty, I find that contract duration is positively related to uncertainty. This result supports the risk-sharing hypothesis, suggesting that labor contracts which are designed to protect workers can effectively reduce their risks. On the other hand, catchers, compared to other position players, devote more human specific capital to their teams. Therefore, I use catcher as a proxy for specific investment. My results reveal that labors who devote more specific human capital will obtain longer contract duration so as to prevent opportunistic behavior from happening.
Finally, according to the characteristics of professional sports teams’ operation, chapter 4 evaluates the efficiency of teams in the National Basketball Association (NBA) and provides suggestions for team executives. Generally, a team’s production structure can be divided into two stages. The first stage transforms salaries into players’ performance; the second stage combines player performance to generate wins and revenues. Under this assumption, I apply the additive efficiency decomposition in two-stage DEA to separate team efficiency into first-stage wage efficiency, second-stage on-court efficiency, and endogenously find out the individual weights for each stage. The empirical results show that NBA teams perform better in first stage than in the second stage. Moreover, NBA teams, on average, tend to possess a higher weight in the first stage, suggesting that team executives can enhance team efficiency more efficaciously by prudentially recruiting players. |
