Abstract:Based on the rational bubbles theory，this study examines the determinants of asset bubbles by using the panel data Logit model and the data of 20 Economies dated from 2000 to 2015. The results suggest that trading volume and price volatility are significantly positive determinants of asset bubbles with the full sample. However，the explainable power of trading volume disappears during the period of severe equity bub- bles. The results also reveal that monetary policy is a determinant of asset bubbles. Credit and its lag term are the two important variables that drive asset bubbles. Besides，this paper investigates the effect of the institu- tional variables on the occurrence of equity bubbles. The results suggest that equity bubbles are more likely to occur in the country with common law system，low protection on small investors，high transparency of govern- ment and free arbitrage. These results are confirmed by the robustness checks.

Abstract:Based on the well-known ( empirical) stylized facts such as infinite activity Lévy jump，stochastic volatility and leverage effect，this paper extends non-Gaussian OU stochastic volatility model，which is pro- posed by Barndorff-Nielsen and Shephard，driven by infinite activity Lévy jump processes. Then the European option pricing model is studied by FFT technology and the principle of structure preserving martingale measure the specific expressions of BNS models driven by different Lévy processes ( Gaussian process，Gamma process and CGMY process) under the risk neutral measures are obtained. Efficient MLE-SMC algorithm，joint sample estimation algorithm and gradient-SMC algorithm are given to estimate the parameters and latent variables of non-Gaussian OU stochastic volatility models using stock and option prices. Finally，in contrast to most exist- ing studies，our model assessment—an empirical research based on the 4. 7 million price data of S&P500 op- tions—is not restricted to the fitting performance，but even takes into account factors like model stability，the exposure to risks arising from the model calibration and the ability to explain observed prices of options. The empirical results show that the pricing effect of in-the-money options is superior to that of the out-of-the-money options. In most cases，the pricing effects of our BNS option pricing models based on joint sample estimation algorithm and gradient-SMC algorithm are better than that of MLE-SMC algorithm.

Abstract:Building an appropriate portfolio to reduce risk is an important goal of portfolio theory. Since the volatility of financial time series tends to be persistent，this characteristic affects the risk of a portfolio’s future returns. This paper constructs an optimal portfolio model with persistent financial asset volatility to reduce the future fluctuation of portfolio returns. By studying the diversification level，the effectiveness of this way of con- structing investment portfolio is investigated. Compared with the mean variance model，our optimal portfolio model of the sequence persistence is better in risk diversification. This study has more important theoretical and practical values in asset portfolio selection.

Abstract:Inthefinancingprocessofstart-ups，theobjectoffinancingandthedesignofcontractswillhavean important impact on the operating status of start-up enterprises and social welfare level. In this paper，the ob- jects of financing are divided into venture capitalists who merely pursue monetary income and strategic inves- tors who pursue both monetary returns and strategic objectives. Based on such classification，this paper studies the choice of financing objects and the design of financing contract among three financing methods: single in- vestor，multiple independent investors and syndicate in staged financing. Ultimately，the optimal financing de- cision for entrepreneurs is given when the primary goal is to social welfare optimization and the secondary target is to maximize an enterprise’s expected return. It is shown that an optimal financing decision should include the optimal financing method and the optimal financing object. In the case of financing approach，when a syn- dicate organization provides financing is feasible，the entrepreneur should seek syndicate financing and this fi- nancing method is always socially efficient; when it is not feasible，the entrepreneur should seek financing from multiple independent investors，however，this financing approach cannot achieve the optimal social wel- fare. Regarding the financing object，the entrepreneur should choose investors whose effort levels are the clo- sest to the first-order optimal effort level.

Abstract:In practice，the manufacturer can control the supplier’s quality by means of business insurance， hence reducing the potential business loss induced by component defects. However，the cost of business insur- ance is relatively high，which may lead suppliers to despise the seriousness of quality problems，and then a- bandon quality improvement. Based on a procurement contract decision model of two-echelon supply chains in single period under complete information，this paper studies how the manufacturer can take advantage of busi- ness insurance to manage the quality risk of supply chains. By comparing the manufacturer’s profits under the no-insurance strategy with that under business insurance strategy，it aims to explore the implementation condi- tions of the business insurance strategy，and gives the optimal purchase contract and the business insurance strategy. Theresultsshowthat: (1) Ifthesupplierissmallinsizeandpoorinanti-riskcapacity，thebusiness insurance strategy can eliminate the constraints of risk tolerance on transactions of the two parties and promote transactions; ( 2) If the supplier is large in size and strong in anti-risk capacity，the manufacturer can take ad- vantage of business insurance strategy to reduce the purchase price of components and to raise the expected profits; ( 3) The optimal strategy for the manufacturer is to insure for the full value if it insures; ( 4) The im- plementation of business insurance does not necessarily lead to a decline in component quality. When the quality cost or the supplier’s risk tolerance is relatively low，there is a complementary effect between business insurance strategy and quality improvement. When both the risk tolerance and the quality cost are high，there is a substitution effect between business insurance strategy and quality improvement.

Abstract:The paper studies a distributor in fresh products supply chain ( cold chain) . The freshness-keeping effort is introduced in order to depict the quantity and quality of the fresh products arriving in the market and the distributor’s optimal decisions. Compared with the previous studies，this paper uses an additive demand function to depict the market demand. Relative enterprise data are used to justify the rationality of this demand function. The paper finds that when the fresh effort is exogenous，the optimal order quantity and the optimal retail price of the distributor are only associated with the freshness-keeping effort. When the retail price is ex- ogenous，the optimal freshness-keeping effort of the distributor depends on the zero point of the first order opti- mization condition of the actual unit cost of the product. When the order quantity is exogenous，the retail price and the profit from freshness-keeping effort increase with the freshness-keeping effort，but the marginal profit from freshness-keeping effort decreases with freshness-keeping effort. Applying the results to Zall Cold Chain， optimal strategies of freshness-keeping effort are suggested.

Abstract:Cooperation in logistics distribution among enterprises can significantly reduce the cost and emission of logistics delivery. Key research questions are how to model cooperation in logistics distribution and develop a cost sharing method. Traditional cost sharing methods need to calculate the cooperative cost for all sub-coalitions，which is equivalent to solving 2N - 1 complex vehicle routing problems for calculating the cooperative cost of 2N - 1 sub-coalitions ( N is the number of enterprises) . This paper analyzes the properties of the cost sharing problem in collaborative distribution by modeling a multi-cooperation vehicle routing. Based on the classical Shapley cost sharing method，a Binary Tree ( B-T) Shapley method is proposed. The new method can not only reduce the computational complexity of cost sharing from O ( N2 2N ) to O ( N2 log2 N) ，but also can N lower the number of vehicle routing problems to be solved from 2 - 1 to 2N - 1. As a result，the cost alloca- tion of collaborative delivery can be completed within a reasonable time. Calculation results of numerical ex- amples and actual cases show that the time needed for the B-T Shapley method is almost negligible compared with that for the Shapley value method. Moreover，the cost allocation results using the B-T Shapley method only have minor deviations compared with those using the Shapley value method，with an average accuracy of a- bout 95% .