隨著不同社會環境的演進，經濟活動亦跟著改變，為了有效運用資源，使其效益達到最大，共享經濟這種創新活動自然而生。共享廠商透過第三方平台把共享設備資訊傳達給承租方，讓共享經濟的類型逐漸的變得具有多樣性。其中使用公共投入如土地的無樁式共享設備，卻很容易製造經濟環境髒亂，產生對社會不利的負的外部性。
本文主要探討免費使用公共投入的共享寡占廠商之最適要素決策行為，透過不確定經濟模型的嚴謹推導，分析政府實施罰金、課稅不同政策對共享廠商利潤期望效用極大化的決策影響，同時也考慮共享廠商具有自主管理行為時，在政府實施罰金及課稅等政策的影響。最後，再分析政府相關政策的社會規劃問題。
本文發現，若寡占市場上相同的共享廠商雇用無樁式共享設備，以提供給消費者共享交通服務。當政府採取罰金政策，在極大的期望利潤效用下，無論風險趨避的共享廠商是否具有自主管理能力，都不會影響共享廠商的最適要素決策及最適產量，其原因為罰金是加法的線型函數，但最適利潤之期望效用水準卻會下降。而當政府採取課稅政策，無論共享廠商是否具有自主管理能力，則共享廠商的最適雇用勞力和資本，以及最適共享服務產量將會減少，但期望利潤效用水準仍會下降。
在分析政府相關政策的社會規劃問題時，我們發現若共享服務市場為寡占型態，不論所有相同的共享廠商有無共享設備的自主管理能力，當共享廠商家數增加使寡占市場獨占力下降，此市場結構改變將會增加同質寡占市場上所發生的外部成本，但不影響政府決定的最適罰金或課稅政策，而會提高最適社會福利水準。

With the development of social environment, economic activities have changed. In order to use resources efficiently and maximize people’s benefits, innovative activities come very naturally such as the sharing economy. Sharing firms can transmit the information of sharing equipment to tenants by the third-party platforms, so the type of sharing economy has gradually varied. Among them, the non-pile sharing equipment using public input such as land bring about a dirty economic environment and produce negative externalities more frequently.
This thesis discusses the optimal factor decisions of the sharing firm that using public input for free. Through rigorous derivations of uncertain economic models, we analyze the impacts of different government policies of fine or tax on the sharing firm’s optimal decision to maximize expected utility of profit. Also, with spontaneous management behavior of the sharing firm, the impacts of fine and tax policies have been analyzed. Finally, we research the social planning problem of relevant government policies in detail.
We find that, if the identical sharing firm on the oligopoly market hire non-pile sharing equipment to produce sharing transportation service for consumers and the government implements a fine policy, regardless of whether the risk-averse sharing firm has self-management behavior, the fine policy will not affect the optimal factors and the optimal output of the sharing firm maximizing expected profit utility. The reason is that the amount of fine is a linear part of the profit function. However, the level of expected utility of the firm’s optimal profit decreases. When the government implements a tax policy, regardless of whether the sharing firm has self-management behavior, the optimal labor and capital hired by the sharing firm and the optimal output will decrease, however, the expected utility of the optimal profit still decreases.
By analyzing the social planning problem of relevant government policies, we found that if the sharing service industry is oligopoly market, regardless of whether the sharing firm has self-management behavior, a much larger number of identical sharing firms or a market structure with less monopoly power will increase the external cost. As a result, the increase in the number of sharing firms will not affect the optimal fine or tax policies determined by the government, but will increase the optimal social welfare.

目錄

第一章 文獻回顧與研究方法 1
第一節 共享經濟的發展 1
第二節 共享經濟分類 5
第三節 有關公共投入的文獻回顧 10
第四節 本文的研究動機與分析架構 12
第二章 有公共投入的共享寡占廠商模型 15
第一節 基本假設與確定模型 15
第二節 有罰金的不確定寡占廠商模型 18
第三節 有政府課稅的不確定寡占廠商模型 24
第四節 有自主管理的不確定寡占廠商罰金模型 31
第五節 有自主管理的不確定寡占廠商課稅模型 38
第六節 不同政策型態的比較 47
第三章 相關政策的社會規劃問題 52
第一節 有罰金的社會規劃模型	52
第二節 有政府課稅的社會規劃模型	57
第三節 有自主管理及罰金的社會規劃模型 60
第四節 有自主管理及課稅的社會規劃模型 64
第五節 不同社會規劃模型的比較 67
第四章  結論 70
參考文獻 73
一、	中文文獻 73
二、	英文文獻 74

 
圖目錄

圖 1 政府課稅政策下對共享廠商最適要素組合之影響 29

 
表目錄

表 1 共享經濟分類 9
表 2 不同政策型態對不確定寡占共享廠商最適要素決策之影響 48
表 3 市場結構型態對不同社會規劃問題最適政策之影響 68

一、	中文文獻
三浦展 (2015)，消費時代：共享經濟，讓人變幸福的大趨勢，時報出版。
王淑燕 (2017)，共享經濟影響因素之複雜模型研究，輔仁大學商學研究所博士論文。
林倖如 (2018)，看日本如何推動共享經濟，提振經濟、解決社會問題，臺灣經濟研究月刊，第41卷，第7期，頁97-107。
胡迪、白仁德 (2017)，臺灣共享經濟發展之觀察分析，土地問題研究季刊，第16卷，第4期，頁100-106。
康廷嶽、黃柏偉 (2015)，由國際共享經濟發展探究我國中小企業商機，中小企業發展季刊，第36期，頁1-29。
楊育菁 (2017)，公共自行車租借使用之環境效益與社會影響評估，國立臺北大學公共事務學院自然資源與環境管理研究所論文。
楊秉訓 (1994)，產量不確定與價格支持之效果，中央研究院經濟研究所經濟論文，第22卷，第1期，頁15-46。
楊秉訓 (2013)，不確定與訊息經濟學，初版，台灣台北:翰蘆圖書。 
廖謹志 (2016)，共享經濟應用於交通運輸業之法律研究，東吳大學法律研究所碩士論文。
鍾冠宇 (2016)，平台式配送服務：基於賽局理論分析一共享經濟下的新型態配送模型，國立臺灣大學資訊管理學研究所論文。

二、	英文文獻
Altenburg, L. (1987), “Production Possibilities with a Public Intermediate Good,” The Canadian Journal of Economics, Malden, Vol. 20, No. 4, pp. 715-734.
Altenburg, L. (1992), “ Some trade theorems with a public intermediate good,” Canadian journal of economics, Vol. XXV, No. 2, pp. 310-332.
Anwar, S. (1998), “ Size of the Government, Welfare and Labour Supply in the Presence of Variable Returns,” International Review of Economics and Finance, Vol. 7, No. 2, pp. 201-208.
Aronsson, T. and S. Wehke (2008), “Public goods, unemployment and policy coordination,” Regional science and urban economics, Vol. 38, No. 3 , pp. 285-298. 
Arrow, K. J. and M. Kurz (1970), “ Optimal growth with irreversible investment in a Ramsey model,” Econometrica Vol. 38, No. 2, pp. 331-344.
Blomquist, S. and V. Christiansen (2005), “The role of prices for excludable public goods,” International tax and public finance, Vol. 12, No. 1, pp. 61-79.
Botsman, R. and R. Rogers (2010), What’s Mine Is Yours: The Rise of Collaborative Consumption, Harpercollins books.
Brennan, G. and C. Walsh (1985), “Private Markets in (Excludable) Public Goods: A Reexamination, Quarterly Journal of Economics, Vol. 100, No. 3, pp. 811-819.
Brito, D. L. and W. H. Oakland (1980), “On the monopolistic provision of excludable public goods,” American economic review, Vol. 70, No. 4, pp. 691-704.
Burns, M. E. and C. Walsh (1981), “Market provision of price-excludable public goods: a general analysis,” Journal of political Economy, Vol. 89, No. 1, pp. 166-191.
Chen, J. H., J. Y. Shieh, C. C. Lai and J. J. Chang (2005), “Productive Public Expenditure and Imperfect Competition with Endogenous Price Markup,” Oxford University Press, Oxford Economic Papers, Vol. 57, No. 3 , pp. 522-544.
Colombier, C. (2008), “Efficiency in public infrastructure provision: a theoretical note,” Journal of economic studies, Vol. 35, No. 6, pp. 528-543.
Craig, S. G. (1987), “The impact of congestion on local public good production,” Journal of public economics, Vol. 32, No. 3, pp. 331-353.
Dixit, A. (1986), “Comparative Statics for Oligopoly,” International Economic Review, Vol. 27, No. 1, pp. 107-122.
Dixon, H. (1987), “The General Theory of Household and Market Contingent Demand,” Manchester School of Economic and Social Studies, Vol. 55, No. 3, pp. 287-304.
Douglas, H. E. and M. E. Lovely (1995), “Scale Economies, Returns to Variety, and the Productivity of Public Infrastructure,” NBER Working Paper Series, Vol. w5295.
Fedeli, S. and F. Forte (2003), “ Public Co-Financing of Private Sector's Investments: Subsidiarity and Corruption,” Public Choice, Dordrecht, Vol. 116, No. 1-2, pp. 109-145.
Felländer, A., C. Ingram and R. Teigland (2015), “ Sharing Economy Embracing Change with Caution,” Entreprenörskaps Forum.
Felson, M. and J. L. Spaeth (1978), “Community Structure and Collaborative Consumption: A Routine Activity Approach,” University of Illinois at Urbana-Champaign.
Fraser, C. D. (1996), “On the provision of excludable public goods,” Journal of public economics, Vol. 60, No. 1, pp. 111-130.
Friedrich, M., M. Hartl and C. Magg (2018), “A modeling approach for matching ridesharing trips within macroscopic travel demand models,” Transportation, New York, Vol. 45, No. 6, pp. 1639-1653.
Futagami, K., Y. Morita and A. Shibata (1993), “Dynamic analysis of an endogenous growth model with public capital,” Scandinavian journal of economics, Vol. 95, No. 4, p. 607.
Gansky, L. (2010), The Mesh: Why the Future of Business Is Sharing, Portfolio Hardcover.
Gorter, H. D. and D. Zilberman (1990), “On the political economy of public good inputs in agriculture,” American journal of agricultural economics, Vol. 72, No. 1, pp. 131-137.
Javier, C. M. (2006), “Public capital and imperfect competition,” Journal of Public Economics, Vol. 90, No. 1-2, pp. 349-387.
Kamien, M. and N. L. Schwartz (1983), “Conjectural variations,” Canadian Journal of Economics, Vol. 16, No. 2, pp. 191-211.
Kellenberg, D. K. (2007), “The provision of public inputs and foreign direct investment,” Contemporary economic policy, Vol. 25, No. 2, pp. 170-184.
Kellermann, K. (2006), “A Note on Intertemporal Fiscal Competition and Redistribution,” International tax and public finance, Vol. 13, No. 2-3, pp. 151-161.
Lee, J. W. (2009), “ Public Spending on Maintenance and Imperfect Competition,” American Economist Vol. 54, No. 2, pp. 28-37.
Leland, H. E. (1972), “Theory of the Firm Facing Uncertain Demand,” American Economic Review, Vol. 62, No. 3, pp. 278-291.
Mankiw, N. G. (1991), “Imperfect Competition and the Keynesian Cross,” New Keynesian economics. Vol. 1, Imperfect competition and sticky prices, pp. 377-385.
Maurer, B. and U. Walz (2000), “Regional Competition for Mobile Oligopolistic Firms- Does Public Provision of Local Inputs Lead to Agglomeration,” Journal of regional science, Vol. 40, No. 2, pp. 353-376.
Ott, I. and S. J. Turnovsky (2006), “Excludable and Non-Excludable Public Inputs: Consequences for Economic Growth,” Economica, New Series, Vol. 73, No. 292, pp. 725-748.
Rougès, J. F. and B. Montreuil (2014), “Crowdsourcing delivery new interconnected business models to reinvent delivery,” Proceedings of Physical Internet Conference.
Schor, J. B. and C. J. Fitzmaurice (2014), “Collaborating and connecting: the emergence of the sharing economy”, Department of Sociology, Boston University, pp. 22- 24.
Spencer, B. J. and J. A. Brander (1983), “Second Best Pricing of Publicly Produced Inputs: The Case of Downstream Imperfect Competition,” Journal of Public Economics, Amsterdam, Vol. 20, No. 2, p. 113.
Tamai, T. (2007), “ Public intermediate goods, endogenous growth, and indeterminacy ,” Economic modelling, Vol. 24, No. 4, pp. 683-689.
Tamai, T. (2009), “ Variety of products, public capital, and endogenous growth,” Economic modelling, Vol. 26, No. 1, pp. 251-255.
Tawada, M. and A. Yanase (2012), “History-dependent paths and trade gains in a small open economy with a public intermediate good,” International economic review, Vol. 53, No. 1, pp. 303-314.
Weymark, J (1987), “Comparative Static Properties of Optimal Nonlinear Income Taxes,” Econometrica, Vol. 55, No. 5, pp. 1165-85.
Yakita, A. (2004), “Elasticity of substitution in public capital formation and economic growth,” Journal of macroeconomics, Vol. 26, No. 3, pp. 391-408.
Yanase, A. and M. Tawada (2017), “Public infrastructure for production and international trade in a small open economy: a dynamic analysis,” Journal of economics, Vol. 121, No. 1, pp. 51-73.
Zervas, G., D. Proserpio and J. Byers (2015), “The rise of the sharing economy: Estimating the impact of airbnb on the hotel industry,” Boston U. School of Management Research Paper (2013-16).