This paper examined the returns earned by subscribing to initial public offerings of equity (IPOs). Rock (1986) suggests that IPO returns are required by uninformed investors as compensation for the risk of trading against superior information. We show that IPOs with more informed investor capital require higher returns. The marketing underwriter's reputation reveals the expected level of "informed" activity. Prestigious underwriters are associated with lower risk offerings. With less risk there is less incentive to acquire information and fewer informed investors. Consequently, prestigious underwriters are associated with IPOs that have lower returns. AN INITIAL PUBLIC OFFERING (IPO) is the first effort by private firms to raise capital in a public equity market. Previous research shows that, on average, the difference between the IPO subscription price and the first secondary market price is greater than a "reasonable" risk premium would require. Thus, it appears that issuing firms and underwriters are deliberately underpricing their IPOs.Several We would like to acknowledge the useful comments of our colleagues Sanjai Bhagat, Jeff Coles, Dick Jefferis, Uri Lowenstein, and Jay Ritter. Our interactions with Dick Jefferis in particular helped to identify and clarify several critical issues. We would also like to thank Jay Ritter for the provision of data. Support from the University of Utah Graduate School of Business, the Garn Institute of Finance, and Iowa State University is gratefully acknowledged. Substantial technical assistance was provided by Denise Woodbury. We would also like to thank the staff at the Chicago Library of Arthur Andersen and Company for their assistance. We alone are responsible for any errors or omissions.1 For a review of empirical research as well as an overview of the IPO process, see Though our model has been influenced by all of this antecedent literature, it is most similar to the model of Rock (1986) and its extension by Beatty and Ritter (1986) (see especially the appendix to their paper). Rock (1986) argues that IPO underpricing compensates uninformed investors for the risk of trading against superior information. In our model, consistent with Rock, the greater the proportion of informed investor capital participating in an IPO, the greater is the equilibrium underpricing. If investors have scarce resources to invest in information acquisition, they specialize in acquiring information for the most uncertain investments. Since informed investor capital migrates to the highly uncertain IPOs, the underpricing and subsequent price run-up for these firms are greater.Underpricing is costly to the issuing firm. Therefore, low risk firms attempt to reveal their low risk characteristic to the market. One way they can do this is by selecting underwriters with high prestige. In this paper, we provide empirical evidence that supports our theoretical result that underwriter prestige is associated with the marketing of low risk IPOs. The empirical analysis is facilitated by our dev...

Abstract. We estimate that the global burden of malaria due to Plasmodium vivax is ϳ70-80 million cases annually. Probably ϳ10-20% of the world's cases of P. vivax infection occur in Africa, south of the Sahara. In eastern and southern Africa, P. vivax represents around 10% of malaria cases but Ͻ 1% of cases in western and central Africa. Outside of African, P. vivax accounts for Ͼ 50% of all malaria cases. About 80-90% of P. vivax outside of Africa occurs in the Middle East, Asia, and the Western Pacific, mainly in the most tropical regions, and 10-15% in Central and South America. Because malaria transmission rates are low in most regions where P. vivax is prevalent, the human populations affected achieve little immunity to this parasite; as a result, in these regions, P. vivax infections affect people of all ages. Although the effects of repeated attacks of P. vivax through childhood and adult life are only rarely directly lethal, they can have major deleterious effects on personal well-being, growth, and development, and on the economic performance at the individual, family, community, and national levels. Features of the transmission biology of P. vivax give this species greater resilience than the less robust Plasmodium falciparum in the face of conditions adverse to the transmission of the parasites. Therefore, as control measures become more effective, the residual malaria burden is likely increasingly to become that of P. vivax.

This paper examined the returns earned by subscribing to initial public offerings of equity (IPOs). Rock (1986) suggests that IPO returns are required by uninformed investors as compensation for the risk of trading against superior information. We show that IPOs with more informed investor capital require higher returns. The marketing underwriter's reputation reveals the expected level of "informed" activity. Prestigious underwriters are associated with lower risk offerings. With less risk there is less incentive to acquire information and fewer informed investors. Consequently, prestigious underwriters are associated with IPOs that have lower returns. AN INITIAL PUBLIC OFFERING (IPO) is the first effort by private firms to raise capital in a public equity market. Previous research shows that, on average, the difference between the IPO subscription price and the first secondary market price is greater than a "reasonable" risk premium would require. Thus, it appears that issuing firms and underwriters are deliberately underpricing their IPOs.Several We would like to acknowledge the useful comments of our colleagues Sanjai Bhagat, Jeff Coles, Dick Jefferis, Uri Lowenstein, and Jay Ritter. Our interactions with Dick Jefferis in particular helped to identify and clarify several critical issues. We would also like to thank Jay Ritter for the provision of data. Support from the University of Utah Graduate School of Business, the Garn Institute of Finance, and Iowa State University is gratefully acknowledged. Substantial technical assistance was provided by Denise Woodbury. We would also like to thank the staff at the Chicago Library of Arthur Andersen and Company for their assistance. We alone are responsible for any errors or omissions.1 For a review of empirical research as well as an overview of the IPO process, see Though our model has been influenced by all of this antecedent literature, it is most similar to the model of Rock (1986) and its extension by Beatty and Ritter (1986) (see especially the appendix to their paper). Rock (1986) argues that IPO underpricing compensates uninformed investors for the risk of trading against superior information. In our model, consistent with Rock, the greater the proportion of informed investor capital participating in an IPO, the greater is the equilibrium underpricing. If investors have scarce resources to invest in information acquisition, they specialize in acquiring information for the most uncertain investments. Since informed investor capital migrates to the highly uncertain IPOs, the underpricing and subsequent price run-up for these firms are greater.Underpricing is costly to the issuing firm. Therefore, low risk firms attempt to reveal their low risk characteristic to the market. One way they can do this is by selecting underwriters with high prestige. In this paper, we provide empirical evidence that supports our theoretical result that underwriter prestige is associated with the marketing of low risk IPOs. The empirical analysis is facilitated by our dev...

This paper examined the returns earned by subscribing to initial public offerings of equity (IPOs). Rock (1986) suggests that IPO returns are required by uninformed investors as compensation for the risk of trading against superior information. We show that IPOs with more informed investor capital require higher returns. The marketing underwriter's reputation reveals the expected level of "informed" activity. Prestigious underwriters are associated with lower risk offerings. With less risk there is less incentive to acquire information and fewer informed investors. Consequently, prestigious underwriters are associated with IPOs that have lower returns. AN INITIAL PUBLIC OFFERING (IPO) is the first effort by private firms to raise capital in a public equity market. Previous research shows that, on average, the difference between the IPO subscription price and the first secondary market price is greater than a "reasonable" risk premium would require. Thus, it appears that issuing firms and underwriters are deliberately underpricing their IPOs.Several We would like to acknowledge the useful comments of our colleagues Sanjai Bhagat, Jeff Coles, Dick Jefferis, Uri Lowenstein, and Jay Ritter. Our interactions with Dick Jefferis in particular helped to identify and clarify several critical issues. We would also like to thank Jay Ritter for the provision of data. Support from the University of Utah Graduate School of Business, the Garn Institute of Finance, and Iowa State University is gratefully acknowledged. Substantial technical assistance was provided by Denise Woodbury. We would also like to thank the staff at the Chicago Library of Arthur Andersen and Company for their assistance. We alone are responsible for any errors or omissions.1 For a review of empirical research as well as an overview of the IPO process, see Though our model has been influenced by all of this antecedent literature, it is most similar to the model of Rock (1986) and its extension by Beatty and Ritter (1986) (see especially the appendix to their paper). Rock (1986) argues that IPO underpricing compensates uninformed investors for the risk of trading against superior information. In our model, consistent with Rock, the greater the proportion of informed investor capital participating in an IPO, the greater is the equilibrium underpricing. If investors have scarce resources to invest in information acquisition, they specialize in acquiring information for the most uncertain investments. Since informed investor capital migrates to the highly uncertain IPOs, the underpricing and subsequent price run-up for these firms are greater.Underpricing is costly to the issuing firm. Therefore, low risk firms attempt to reveal their low risk characteristic to the market. One way they can do this is by selecting underwriters with high prestige. In this paper, we provide empirical evidence that supports our theoretical result that underwriter prestige is associated with the marketing of low risk IPOs. The empirical analysis is facilitated by our dev...

Human T-lymphotropic virus type 1 (HTLV-1) persists by driving clonal proliferation of infected T lymphocytes. A high proviral load predisposes to HTLV-1-associated diseases. Yet the reasons for the variation within and between persons in the abundance of HTLV-1-infected clones remain unknown. We devised a highthroughput protocol to map the genomic location and quantify the abundance of > 91 000 unique insertion sites of the provirus from 61 HTLV-1 ؉ persons and > 2100 sites from in vitro infection. We show that a typical HTLV-1-infected host carries between 500 and 5000 unique insertion sites. We demonstrate that negative selection dominates during chronic infection, favoring establishment of proviruses integrated in transcriptionally silenced DNA: this selection is significantly stronger in asymptomatic carriers. We define a parameter, the oligoclonality index, to quantify clonality. The high proviral load characteristic of HTLV-1- IntroductionHuman T-lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATLL), HTLV-1-associated myelopathy/ tropical spastic paraparesis (HAM/TSP), uveitis, and infective dermatitis. It is estimated that 15 to 20 million persons live with HTLV-1 infection worldwide. A small proportion (up to 7%, depending on the area) of HTLV-1-infected persons develop disease, whereas the majority remain asymptomatic carriers (ACs). Infection occurs via breastfeeding, transfusion of infected cellular blood products, or sexual intercourse. Symptoms appear after a long period (years or decades) of clinical latency. 1 The HTLV-1 proviral load (PVL) remains stable within each infected person and correlates with the outcome of infection. However, the PVL varies widely among infected people, even within a particular diagnostic group. [2][3][4] The sequence of HTLV-1 is also stable within a person, 5,6 indicating that the PVL is maintained in vivo mainly by mitosis of infected cells during the chronic phase of the infection. This interpretation is supported by the observation that individual clones of infected cells can persist in patients for several years. 7-9 Thus, it has been hypothesized that infectious transmission of HTLV-1 is important early in infection across the virologic synapse, 10 whereas mitotic replication is responsible for maintaining proviral load once a persistent infection has been established and reached an equilibrium with the immune response. 11 In approximately 5% of infected people, persistent clonal proliferation culminates in malignant transformation in the disease ATLL. 7,8 The leukemic clones carry generally one (complete or defective) provirus per cell. [12][13][14] There has been a longstanding debate on the question of whether HTLV-1 is latent or persistently expressed in vivo. Persistent expression is strongly suggested by the extensive evidence that the strong, chronically activated cytotoxic T lymphocyte (CTL) response to HTLV-1 limits the proviral load and reduces the risk of HAM/TSP. 11 Furthermore, there is both experimental evidence 15 and th...