Operations Management under Financial Frictions

The main purpose of this dissertation is to study the emerging operations issues under financial frictions, in the contexts of supply chain finance and crowdfunding platform; and to identify the implications for individuals and businesses. In Chapter 1, A Supply Chain Theory of Factoring and Reverse Factoring , we develop a supply chain theory of factoring (recourse and non-recourse) and reverse factoring showing when these post-shipment financing schemes should be adopted and who really benefits from the adoption. Factoring is a financial arrangement where the supplier sells accounts receivable to the factor against a premium, and receives cash for immediate working capital needs. Reverse factoring takes advantage of the credit rating discrepancy between small supplier and large retailer, and enables supplier\u27s factoring at the retailer\u27s rate. Given the supplier\u27s credit rating and the trade credit term, recourse factoring is preferred when the supplier\u27s cash investment return rate is relatively high; non-recourse factoring is preferred within certain medium range; otherwise, factoring should not be adopted. Both factoring schemes, if adopted, benefit both the supplier and the retailer, and thus the overall supply chain. Further, we find that reverse factoring may not be always preferred by suppliers among other short-term financing options (bank loans, recourse and non-recourse factoring). Retailers should only offer reverse factoring to suppliers with low, but above a threshold, to medium cash investment return rates. The optimally designed reverse factoring program can always increase the retailer\u27s profit, but it may leave the supplier indifferent to his current financing option when followed by aggressive payment extension. Interestingly, our results suggest that it is often preferable for the retailer to extend reverse factoring to certain suppliers without any request for payment extension, and leverage the supplier\u27s willingness to carry extra inventory that increases the overall supply chain efficiency. In Chapter 2, Crowdfunding under Social Learning and Network Externalities , we investigate how the presence of both social learning and network externalities affects the strategic interaction between a crowdfunding firm and forward-looking consumers. In rewards-based crowdfunding, a firm (campaigner) pre-sells a new product and solicits financial contributions from the crowd (consumers) to cover production costs. When a crowdfunding product with uncertain quality is first introduced, consumers may choose to strategically delay their purchase in anticipation of product quality reviews. Our research yields three main insights. First, we find that in the presence of social learning and strong network externalities, an upward-sloping demand curve may arise. This so-called \textit{Veblen effect} occurs due to the interaction between social learning and strong network externalities. Second, we show that network externalities have important implications for the optimal crowdfunding reward choice. In particular, under strong network externalities, the optimal reward will induce all consumers to either adopt the product early or adopt the product late; whereas under weak network externalities, the consumers will possibly adopt the products in different periods. Third, we characterize the optimal reward strategy under financial constraints and quantify its impact on the optimal reward choice and the induced purchase pattern from consumers. These insights provide useful guidance on how firms can exploit the benefits of crowdfunding. In Chapter 3, Crowdfunding vs. Bank Financing: Effects of Market Uncertainty and Word-of-Mouth Communication , we investigate a firm\u27s optimal funding choice when launching an innovative product to the market with both market uncertainty and word-of-mouth (WoM) communication. Bank financing is a traditional source of capital for small businesses, whereas crowdfunding has recently emerged as an alternative fund-raising solution to support innovative ideas and entrepreneurial ventures. Conceivably, crowdfunding could potentially replace some of the conventional roles of bank financing, but puzzles linger over when crowdfunding is a better funding choice. We characterize the firm\u27s optimal pricing strategies under the two funding choices (i.e., bank financing and crowdfunding), compare their performances, and investigate the corresponding implications on social welfare. Among other results, we find that the firm\u27s optimal funding choice and pricing strategy depend critically on the market uncertainty, the WoM, and the initial investment requirement. More specifically, the firm would adopt intertemporal pricing under crowdfunding, where the exact format is determined by the WoM and market uncertainty; under bank financing, however, the firm should always charge a fixed price invariant to those parameters. Moreover, market uncertainty has a non-monotonic effect on the optimal funding choice: Bank financing is preferred only when the market uncertainty is within an intermediate range. The impact of initial investment requirement on the choice of funding schemes shares qualitatively a similar trend. Finally, contrary to the conventional wisdom, we find that more active social interactions in crowdfunding, although beneficial to the firm, may hurt consumers and even reduce social welfare

Burden of disease resulting from chronic mountain sickness among young Chinese male immigrants in Tibet

BACKGROUND: In young Chinese men of the highland immigrant population, chronic mountain sickness (CMS) is a major public health problem. The aim of this study was to measure the disease burden of CMS in this population. METHODS: We used disability-adjusted life years (DALYs) to estimate the disease burden of CMS. Disability weights were derived using the person trade-off methodology. CMS diagnoses, symptom severity, and individual characteristics were obtained from surveys collected in Tibet in 2009 and 2010. The DALYs of individual patients and the DALYs/1,000 were calculated. RESULTS: Disability weights were obtained for 21 CMS health stages. The results of the analyses of the two surveys were consistent with each other. At different altitudes, the CMS rates ranged from 2.1-37.4%; the individual DALYs of patients ranged from 0.13-0.33, and the DALYs/1,000 ranged from 3.60-52.78. The age, highland service years, blood pressure, heart rate, smoking rate, and proportion of the sample working in engineering or construction were significantly higher in the CMS group than in the non-CMS group (p < 0.05). These variables were also positively associated with the individual DALYs (p < 0.05). Among the symptoms, headaches caused the largest proportion of DALYs. CONCLUSION: The results show that CMS imposes a considerable burden on Chinese immigrants to Tibet. Immigrants with characteristics such as a higher residential altitude, more advanced age, longer highland service years, being a smoker, and working in engineering or construction were more likely to develop CMS and to increase the disease burden. Higher blood pressure and heart rate as a result of CMS were also positively associated with the disease burden. The authorities should pay attention to the highland disease burden and support the development and application of DALYs studies of CMS and other highland diseases

Lineage diversification and historical demography of a montane bird Garrulax elliotii - implications for the Pleistocene evolutionary history of the eastern Himalayas

<p>Abstract</p> <p>Background</p> <p>Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in many extant species. In montane habitats, species' ranges may have expanded and contracted along an altitudinal gradient in response to environmental fluctuations leading to alternating periods of genetic isolation and connectivity. Because species' responses to climate change are influenced by interactions between species-specific characteristics and local topography, diversification pattern differs between species and locations. The eastern Himalayas is one of the world's most prominent mountain ranges. Its complex topography and environmental heterogeneity present an ideal system in which to study how climatic changes during Pleistocene have influenced species distributions, genetic diversification, and demography. The Elliot's laughing thrush (<it>Garrulax elliotii</it>) is largely restricted to high-elevation shrublands in eastern Himalayas. We used mitochondrial DNA and microsatellites to investigate how genetic diversity in this species was affected by Pleistocene glaciations.</p> <p>Results</p> <p>Mitochondrial data detected two partially sympatric north-eastern and southern lineages. Microsatellite data, however, identified three distinct lineages congruent with the geographically separated southern, northern and eastern eco-subregions of the eastern Himalayas. Geographic breaks occur in steep mountains and deep valleys of the Kangding-Muli-Baoxin Divide. Divergence time estimates and coalescent simulations indicate that lineage diversification occurred on two different geographic and temporal scales; recent divergence, associated with geographic isolation into individual subregions, and historical divergence, associated with displacement into multiple refugia. Despite long-term isolation, genetic admixture among these subregional populations was observed, indicating historic periods of connectivity. The demographic history of <it>Garrulax elliotii </it>shows continuous population growth since late Pleistocene (about 0.125 mya).</p> <p>Conclusion</p> <p>While altitude-associated isolation is typical of many species in other montane regions, our results suggest that eco-subregions in the eastern Himalayas exhibiting island-like characteristics appear to have determined the diversification of <it>Garrulax elliotii</it>. During the Pleistocene, these populations became isolated on subregions during interglacial periods but were connected when these expanded to low altitude during cooler periods. The resultant genetic admixture of lineages might obscure pattern of genetic variation. Our results provide new insights into sky island diversification in a previously unstudied region, and further demonstrate that Pleistocene climatic changes can have profound effects on lineage diversification and demography in montane species.</p

CYP2J2-Derived EETs Attenuated Angiotensin II-Induced Adventitial Remodeling via Reduced Inflammatory Response

Background: Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acids (AA) to form epoxyeicosatrienoic acids (EETs), which exert beneficial roles in the treatment of cardiovascular diseases, but little is known about its role on adventitial remodeling. Methods: We used C57BL/6J mice in vivo and primary rat adventitial fibroblasts (AFs) in vitro treated with Angiotensin II to investigate the effects of CYP2J2 gene delivery and exogenous EETs administration on adventitial remodeling. Results: CYP/sEH system was found to exist in human adventitia, and involved in adventitial remodeling process. Exogenous EETs administration significantly inhibited Ang II-induced AFs activation, characterized by differentiation, proliferation, migration, and collagen synthesis. These protective effects were partially reversed by PPAR&#947; antagonist GW9662 pretreatment or SOCS3 siRNA transfection. EETs suppressed Ang II-induced I&#954;Bα phosphorylation, subsequent NF-&#954;B nuclear translocation via PPAR&#947; dependent signaling pathway in AFs. Additionally, EETs reduced Ang II-induced JAK2, STAT3 phosphorylation and subsequent phosphor-STAT3 nuclear translocation, which were mediated by SOCS3 induction but independent of PPAR&#947; activation. Furthermore, rAAV-CYP2J2 gene delivery reduced vessel wall thickening, AFs differentiation, proliferation and collagen deposition in aortic adventitia induced by Ang II infusion, which were mediated by NF-&#954;B and SOCS3/JAK/STAT signaling pathways in blood pressure dependent and independent manner, respectively. Conclusion: We concluded that CYP2J2 overexpression attenuated Ang II-induced adventitial remodeling via PPAR&#947;-dependent NF-&#954;B and PPAR&#947;-independent SOCS3/JAK/STAT inflammatory signaling pathways

Burden of disease resulting from chronic mountain sickness among young Chinese male immigrants in Tibet

Abstract Background In young Chinese men of the highland immigrant population, chronic mountain sickness (CMS) is a major public health problem. The aim of this study was to measure the disease burden of CMS in this population. Methods We used disability-adjusted life years (DALYs) to estimate the disease burden of CMS. Disability weights were derived using the person trade-off methodology. CMS diagnoses, symptom severity, and individual characteristics were obtained from surveys collected in Tibet in 2009 and 2010. The DALYs of individual patients and the DALYs/1,000 were calculated. Results Disability weights were obtained for 21 CMS health stages. The results of the analyses of the two surveys were consistent with each other. At different altitudes, the CMS rates ranged from 2.1-37.4%; the individual DALYs of patients ranged from 0.13-0.33, and the DALYs/1,000 ranged from 3.60-52.78. The age, highland service years, blood pressure, heart rate, smoking rate, and proportion of the sample working in engineering or construction were significantly higher in the CMS group than in the non-CMS group (p p  Conclusion The results show that CMS imposes a considerable burden on Chinese immigrants to Tibet. Immigrants with characteristics such as a higher residential altitude, more advanced age, longer highland service years, being a smoker, and working in engineering or construction were more likely to develop CMS and to increase the disease burden. Higher blood pressure and heart rate as a result of CMS were also positively associated with the disease burden. The authorities should pay attention to the highland disease burden and support the development and application of DALYs studies of CMS and other highland diseases.</p