國際航空觀光旅次需求行為動態模式之研究

Abstract

過去十年來，亞洲地區航空客運業成長快速，台灣地區人民出國旅遊的旅次量成長近1.5倍，平均成長率為4.13%。在社會經濟方面國民生產毛額(GDP)亦達到1.45倍的成長，顯示國人越來越有能力出國旅遊，且對於生活品質更加重視。檢視歷史資料顯示，由於實質所得增加而造成出國旅遊需求的上升並不僅反應在當期，兩者間存有時間延遲(time lag)。民國92年發生的SARS事件或民國77年開放大陸探親後，皆立即造成出國旅遊需求的巨幅波動，且其影響不止於當年，甚至牽動到未來數年旅遊產業的景氣。過去有關消費者航空旅遊選擇模式的研究，多只考慮當期的變數影響當期消費者選擇之靜態模式，而較少考慮當期因素與決策影響未來預期行為的動態模式。 本研究目的在於探討時間因素對個體出國旅遊選擇之影響。個體選擇的效用函數由個體金錢與時間方面的能力與外在環境影響因子組成。為討論不同時間對旅遊行為的影響，本研究將時間偏好率分為對過去旅遊行為與對未來預期的旅遊行為兩種，以時間偏好率折算過去與未來時期旅遊行為之效用。效用函數中旅遊預算受前期旅遊行為影響，各時期的外在環境因子與時間限制亦不同，個體在預算與時間限制之下追求最大的總折現效用值。本研究繼而以遞迴之方式找出個體於未來時期最適之旅遊時機。在實證資料上本研究以問卷之方式調查收集個體各項關於出國旅遊行為的特性與偏好，並以此資料校估模式參數。本研究並引用台灣地區近10年來出國旅次量與所得資料，進行外在環境因子的估計，以特定航線的旅遊行程進行範例分析，驗證模式之可行性。此外進一步分析不同所得層級個體與其出國旅遊選擇機率之關係，另以發生SARS事件的民國92年為例，以模式評估其後兩年個體的出國旅遊行為。 研究結果顯示效用函數中的旅遊預算、休假天數、旅遊花費與旅遊行程天數在統計檢定上皆為顯著，對模式影響程度依序為旅遊花費佔旅遊預算之比例與休假天數，其次為旅遊預算與旅遊行程天數。研究結果亦顯示個體對過去旅遊經驗較重視，過去旅遊行為的效用折減因子為53.22％，而對未來預期旅遊行為的效用折減因子僅為13.23％，模式中總折現效用值受過去旅遊行為影響較大，考量時間範圍為四年，而在未來預期的旅遊行為方面考量範圍僅為兩年。

Air transport industry in Asia grows rapidly in the past decade. In Taiwan, the number of outbound travelers in 2005 is almost 1.5 times more than that in 1996, with an average of 4.13% growth rate. GDP in 2005 is 1.45 times more than 1996, and indicates that Taiwan people afford more the expense for oversea travel, and emphasize more on the quality of life. From past data about travel and tourism, increase in real income doesn’t response immediately to travel demand, and there exists time lag. After SARS in 2003 or opening relative visit on the mainland in 1988, outbound travel demand has huge fluctuations, which demand even lasted in the following few years. Past studies in tourists’ discrete travel choice model seldom concern variables affecting individual decision in dynamic concept. This study aims to investigate the effect of time factor on international air travel tourism demand. This study constructs an intertemporal travel choice model, in which utility functions are composed of two main factors: individuals’ ability to travel, including money and time, and external environment factor. To explore the impact of past travel experiment and future expected travel on current choice, this study divides time preferences into those for past travel and for future travel, and uses time preference to convert utility in each periods into current period. In utility function, travel budget is affected by travel decisions made in pervious period, and external environment factor and time constraint are also different in each period. This study assumes individual aims on maximizing the aggregated utility, with various discounts on different periods subject to budget and time constraints. Furthermore, the optimal timing for travel in future period is obtained by a recursive method. In parameter calibration, this study design questionnaire and obtains the data about individual character and preference in outbound travel. The study further uses the real number of outbound travelers and income data in Taiwan in the past decade to estimate external environment factor. And take some international tour routes for example to illustrate the application of the model. Furthermore, the study analyze the differences on outbound travel choice probability among different income individuals, and take the example of SARS in 2003, to show the effect of external environmental factor on the optimal timing for outbound travel. The results show that travel budget, off-days, travel expenditure and travel duration in the utility function significantly affect individual travel demand. With regard to time preference, the effect of excepted travel in future on the current travel decision is smaller than that of past travel experience. The results also show past travel experiments will influence the current travel decision up to four years; however, for future expected travel behavior, it is merely two years