A Rude Awakening: Internet Shakeout in 2000

This study explores the major value-drivers of business-to-consumer ("B2C") Internet companies' share prices both before and after the "bursting of the Internet bubble" in the spring of 2000. Although many market observers had predicted that the bubble would eventually burst (e.g., Perkins and Perkins 1999), the ultimate and previously unanswered challenge lay identifying which stocks would fall and which ones would survive the shakeout. We develop an empirical valuation model and provide evidence that the Internet stocks that this model suggests were relatively over-valued prior to the Internet stock market correction experienced relatively larger drops in their price-to-sales ratios when the bubble burst. This result is robust to the inclusion of competing explanatory variables suggested by the economics literature related to industry rationalizations. We also investigate a number of additional issues related to the rapidly changing Internet world. First, we provide descriptive evidence of the correlation between monthly stock returns and contemporaneous and lagged Nielsen/Netratings web traffic metrics (both levels and changes). We then undertake a factor analysis on the set of Nielsen/Netratings raw web metrics with a view to synthesizing the data into a parsimonious set of orthogonal web performance measures. Our factor analysis results in the extraction of three factors that capture the most relevant dimensions of website performance: (1) reach, (2) "stickiness", and (3) customer loyalty. Our findings suggest that all three web performance measures are value-relevant to the share prices of Internet companies in each of 1999 and 2000. Our findings of significance for the year 2000 contradict the recent claims of some analysts that web traffic measures are no longer important. We also explore the valuation role of our proxy for B2C companies' ability to sustain their current rate of "cash burn" and find that this proxy is a significant value-driver in each of 1999 and 2000. Finally, our results suggest that investors adopted a more skeptical attitude towards expenditures on intangible investments as the Internet sector began to mature. Consistent with the results of prior studies in other knowledge asset based industries, we find that investors appear to implicitly capitalize product development (R&D) and advertising expenses (customer acquisition costs) during the "bubble" period when the market was more optimistic about the prospects of B2C companies. However, neither marketing expenses nor product development costs are implicitly capitalized into value, on average, subsequent to the shakeout in the spring of 2000. Overall, our study provides a preliminary view of the shakeout and maturation of one of the most important New Economy industries to emerge to date - the Internet

Career Concerns and Earnings Management

Motivated by the disconnect between survey evidence documenting that executives prioritize implicit contracting (i.e., labor market based career concerns) when making earnings management decisions (Graham et al (2005)) and the extant literature’s focus on explicit contracting to explain earnings manipulation, we examine analytically the role of managerial career concerns in earnings management. Building on Holmstrom (1982, 1999), we present a career concerns based earnings management model that incorporates the unique reversing nature of earnings management. A key insight derived from the model is that whether the predictions of a traditional career concerns model prevail, which is to say that managers engage in more income-increasing behavior in their early years, critically depends upon the reversal characteristics of the earnings management vehicle chosen

Altmetric for Books: Informing commissioning and data-driven decisions

This presentation was given as part of a webinar on using Altmetric data to inform editorial/acquisitions strategy for bookshttps://deepblue.lib.umich.edu/bitstream/2027.42/148278/1/Plan for Altmetric Webinar.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148278/2/Altmetric-AcademicBookWeek-Webinar-20190307.pdfDescription of Plan for Altmetric Webinar.pdf : TextDescription of Altmetric-AcademicBookWeek-Webinar-20190307.pdf : Slide

Effects of Short Term Exposure to Elevated Predation Risk on the Learning of a Novel Foraging Task in Female Trinidadian Guppies (Poecilia reticulata)

Predation pressure is an important selection pressure that shapes prey morphology, life history and behaviours. Long-term exposure to high predation risk is known to shape learning, but the effects of short-term exposure to high predation risk on learning are less understood. Short-term exposure to elevated predation risk (using conspecific alarm cues) induces neophobia, which can have direct survival benefits for prey. Neophobia is also naturally occurring in certain wild populations, and is known to shape foraging related learning. However, the effects of risk induced neophobia on foraging related learning are unknown. The aim of this thesis was to examine the effects of short-term exposure to elevated predation risk on the learning of a novel foraging task. I designed an experiment where wild caught Trinidadian guppies were exposed to different background levels of predation risk. They were subsequently trained to associate a food reward with a coloured object over 4 days, during which they received acute risk reinforcement stimuli. Results show that background risk had no effect on the learning of the novel foraging task. Both high and low predation risk treatments learned the foraging task equally well. However, while acute risk did constrain learning, it did not inhibit it. No evidence was found that the learned association could be generalized across contexts. However, a significant side bias in the data, where the right side of the tank was preferred over the left, prevented any firm conclusions. Future studies might disentangle the effects of short-term background risk and acute risk on the learning of a novel foraging task

Overexpressed Genes/ESTs and Characterization of Distinct Amplicons on 17823 in Breast Cancer Cells

Abstract17823 is a frequent site of gene amplification in breast cancer. Several lines of evidence suggest the presence of multiple amplicons on 17823. To characterize distinct amplicons on 17823 and localize putative oncogenes, we screened genes and expressed sequence tags (ESTs) in existing physical and radiation hybrid maps for amplification and overexpression in breast cancer cell lines by semiquantitative duplex PCR, semiquantitative duplex RT-PCR, Southern blot, Northern blot analyses. We identified two distinct amplicons on 17823, one including TBX2 and another proximal region including RPS6KB1 (PS6K) and MUL. In addition to these previously reported overexpressed genes, we also identified amplification and overexpression of additional uncharacterized genes and ESTs, some of which suggest potential oncogenic activity. In conclusion, we have further defined two distinct regions of gene amplification and overexpression on 17823 with identification of new potential oncogene candidates. Based on the amplification and overexpression patterns of known and as of yet unrecognized genes on 17823, it is likely that some of these genes mapping to the discrete amplicons function as oncogenes and contribute to tumor progression in breast cancer cells

Can the "brick wall" model present the same results in different coordinate representations?

By using the 't Hooft's "brick wall" model and the Pauli-Villars regularization scheme we calculate the statistical-mechanical entropies arising from the quantum scalar field in different coordinate settings, such as the Painlev\'{e} and Lemaitre coordinates. At first glance, it seems that the entropies would be different from that in the standard Schwarzschild coordinate since the metrics in both the Painlev\'{e} and Lemaitre coordinates do not possess the singularity at the event horizon as that in the Schwarzschild-like coordinate. However, after an exact calculation we find that, up to the subleading correction, the statistical-mechanical entropies in these coordinates are equivalent to that in the Schwarzschild-like coordinate. The result is not only valid for black holes and de Sitter spaces, but also for the case that the quantum field exerts back reaction on the gravitational field provided that the back reaction does not alter the symmetry of the spacetime.Comment: 8 pages, Phys. Rev. D in pres

Drug Susceptibility Patterns of Mycobacterium Tuberculosis from Adults With Multidrug-Resistant Tuberculosis and Implications for a Household Contact Preventive Therapy Trial

BACKGROUND: Drug susceptibility testing (DST) patterns of Mycobacterium tuberculosis (MTB) from patients with rifampicin-resistant tuberculosis (RR-TB) or multidrug-resistant TB (MDR-TB; or resistant to rifampicin and isoniazid (INH)), are important to guide preventive therapy for their household contacts (HHCs). METHODS: As part of a feasibility study done in preparation for an MDR-TB preventive therapy trial in HHCs, smear, Xpert MTB/RIF, Hain MTBDRplus, culture and DST results of index MDR-TB patients were obtained from routine TB programs. A sputum sample was collected at study entry and evaluated by the same tests. Not all tests were performed on all specimens due to variations in test availability. RESULTS: Three hundred eight adults with reported RR/MDR-TB were enrolled from 16 participating sites in 8 countries. Their median age was 36 years, and 36% were HIV-infected. Routine testing on all 308 were confirmed as having RR-TB, but only 75% were documented as having MDR-TB. The majority of those not classified as having MDR-TB were because only rifampicin resistance was tested. At study entry (median 59 days after MDR-TB treatment initiation), 280 participants (91%) were able to produce sputum for the study, of whom 147 (53%) still had detectable MTB. All but 2 of these 147 had rifampicin DST done, with resistance detected in 89%. Almost half (47%) of the 147 specimens had INH DST done, with 83% resistance. Therefore, 20% of the 280 study specimens had MDR-TB confirmed. Overall, DST for second-line drugs were available in only 35% of the 308 routine specimens and 15% of 280 study specimens. CONCLUSIONS: RR-TB was detected in all routine specimens but only 75% had documented MDR-TB, illustrating the need for expanded DST beyond Xpert MTB/RIF to target preventive therapy for HHC

Measurement of the Lifetime Difference Between B_s Mass Eigenstates

We present measurements of the lifetimes and polarization amplitudes for B_s --> J/psi phi and B_d --> J/psi K*0 decays. Lifetimes of the heavy (H) and light (L) mass eigenstates in the B_s system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203 +/- 15 B_s decays, we obtain tau_L = (1.05 +{0.16}/-{0.13} +/- 0.02) ps and tau_H = (2.07 +{0.58}/-{0.46} +/- 0.03) ps. Expressed in terms of the difference DeltaGamma_s and average Gamma_s, of the decay rates of the two eigenstates, the results are DeltaGamma_s/Gamma_s = (65 +{25}/-{33} +/- 1)%, and DeltaGamma_s = (0.47 +{0.19}/-{0.24} +/- 0.01) inverse ps.Comment: 8 pages, 3 figures, 2 tables; as published in Physical Review Letters on 16 March 2005; revisions are for length and typesetting only, no changes in results or conclusion

Renormalized black hole entropy in anti-de Sitter space via the "brick wall" method

We consider the entropy of a quantum scalar field on a background black hole geometry in asymptotically anti-de Sitter space-time, using the ``brick wall'' approach. In anti-de Sitter space, the theory has no infra-red divergences, and all ultra-violet divergences can be absorbed into a renormalization of the coupling constants in the one-loop effective gravitational Lagrangian. We then calculate the finite renormalized entropy for the Schwarzschild-anti-de Sitter and extremal Reissner-Nordstrom-anti-de Sitter black holes, and show that, at least for large black holes, the entropy is entirely accounted for by the one-loop Lagrangian, apart possibly from terms proportional to the logarithm of the event horizon radius. For small black holes, there are indications that non-perturbative quantum gravity effects become important.Comment: Revtex, 16 pages, no figures. Minor changes. Version accepted for publication in Phys. Rev.

Update: cohort mortality study of workers highly exposed to polychlorinated biphenyls (PCBs) during the manufacture of electrical capacitors, 1940-1998

BACKGROUND: The National Institute for Occupational Safety and Health previously reported mortality for a cohort of workers considered highly exposed to polychlorinated biphenyls (PCBs) between 1939 and 1977 at two electrical capacitor manufacturing plants. The current study updated vital status, examined liver and rectal cancer mortality previously reported in excess in this cohort and evaluated mortality from non-Hodgkin's lymphoma (NHL) and cancers of the stomach, intestine, breast, prostate, skin (melanoma) and brain reported to be in excess in other cohort and case-control studies of PCB-exposed persons. METHODS: Mortality was updated through 1998 for 2572 workers. Age-, gender-, race- and calendar year-adjusted standardized mortality ratios (SMRs) and 95% confidence intervals (CI) were calculated using U.S., state and county referent rates. SMRs using U.S. referent rates are reported. Duration of employment was used as a surrogate for exposure. RESULTS: Consistent with the previous follow-up, mortality from biliary passage, liver and gall bladder cancer was significantly elevated (11 deaths, SMR 2.11, CI 1.05 – 3.77), but mortality from rectal cancer was not (6 deaths, SMR 1.47, CI 0.54 – 3.21). Among women, mortality from intestinal cancer (24 deaths, SMR 1.89, CI 1.21 – 2.82) and from "other diseases of the nervous system and sense organs", which include Parkinson's disease and amyotrophic lateral sclerosis, (15 deaths, SMR 2.07, CI 1.16 – 3.42) were elevated. There were four ALS deaths, all women (SMR 4.35, CI 1.19–11.14). Mortality was elevated for myeloma (7 deaths, SMR 2.11, CI 0.84 – 4.34), particularly among workers employed 10 years or more (5 deaths, SMR 2.80, CI 0.91 – 6.54). No linear associations between mortality and duration of employment were observed for the cancers of interest. CONCLUSION: This update found that the earlier reported excess in this cohort for biliary, liver and gall bladder cancer persisted with longer follow-up. Excess mortality for intestinal cancer among women was elevated across categories of duration of employment; myeloma mortality was highest among those working 10 years or more. The small numbers of deaths from liver and intestinal cancers, myeloma and nervous system diseases coupled with the lack of an exposure-response relationship with duration of employment preclude drawing definitive conclusions regarding PCB exposure and these causes of death