An EM algorithm for the destructive COM-Poisson regression cure rate model

In this paper, we consider a competitive scenario and assume the initial number of competing causes to undergo a destruction after an initial treatment. This brings in a more realistic and practical interpretation of the biological mechanism of the occurrence of tumor since what is recorded is only from the undamaged portion of the original number of competing causes. Instead of assuming any particular distribution for the competing cause, we assume the competing cause to follow a Conway–Maxwell Poisson distribution which brings in flexibility as it can handle both over-dispersion and under-dispersion that we usually encounter in count data. Under this setup and assuming a Weibull distribution to model the time-to-event, we develop the expectation maximization algorithm for such a flexible destructive cure rate model. An extensive simulation study is carried out to demonstrate the performance of the proposed estimation method. Finally, a melanoma data is analyzed for illustrative purpose.     

Hero shots: involved fathers conquering new discursive territory in consumer culture

ABSTRACT

In this paper, we explore how visual expressions of culture offer new discursive territory within which consumer cultural ideals can be negotiated on a global scale. Through a critical visual analysis of the revelatory case Swedish Dads, we find hero shots depicting involved fathers where children’s needs and the hermetic confines of the home take center stage, as opposed to the traditional fatherhood ideals portrayed in western contemporary advertising, media, and popular culture. We demonstrate how the Swedish state’s gender ideology was encoded into a communicative event in the form of hero shots and subsequently dispersed by visual consumers as well as political and commercial stakeholders pushing this particular agenda and/or capitalizing on its tendencies. This in such a way that the event conquered new discursive territory fostering new types of consumer cultural negotiations on fatherhood ideals also in other cultural settings.     

Growing Followers: Exploring the Effects of Leader Humility on Follower Self‐Expansion,Self‐Efficacy,and Performance

Although the effectiveness of leader humility has been well documented, our understanding of how leader humility influences followers psychologically is limited. Surpassing a mere leader‐centric understanding of the leader influence process by more fully understanding how leadership behavior shapes followers psychologically has been identified as a critical need by leadership scholars. Drawing on self‐expansion theory, we argue that leader humility triggers followers’ self‐expansion and that this psychological change enhances followers’ self‐efficacy, which in turn contributes to followers’ task performance. We also argue that the relationship between leader humility and followers’ self‐expansion is strengthened when leaders and followers are similar in age and gender. Using a time‐lagged research design with responses from 256 leader–follower dyads, we found support for our proposed model. We discuss the theoretical implications for our findings and suggest areas for future research.     

Total factor productivity growth in banking: The Israeli banking sector 1979–1982

The primary focus of this paper is the modeling and estimation of total factor productivity growth in banking. The measured total factor productivity growth is decomposed into its main components: 1) scale economy and output growth, 2) branching effect, and 3) technological change effect. Our findings indicate that total factor productivity grew at an annual average rate of 7.8% for the 1979–1982 period but this growth has slowed down to only 2.9% for the 1981–1982 period. Scale economy and output growth have contributed to about four-fifths of the growth, whereas branch growth and technical change have contributed to one-fifth of the growth. An important observation is the increasing importance of both branch growth and technical change throughout the period, especially for smaller banks.The refereeing process of this paper was handled by J. van den Broeck.     

March Market Madness: The Impact of Value‐Irrelevant Events on the Market Pricing of Earnings News

Each year, the NCAA basketball tournament (March Madness) is a daytime distraction for millions of people, providing a largely exogenous shock to investor attention. We investigate whether March Madness influences the market response to earnings by diverting investor attention away from earnings news. We find that the price reaction to earnings news released during March Madness is muted. This result generally holds across several samples and additional analyses. We also find that the result is more muted for low institutional ownership firms, consistent with the effect being driven by less‐sophisticated investors. Furthermore, we find that it takes the market 30 to 60 days to correct for the distraction effect. Overall, we provide a unique test of the theory of limited attention by documenting that extraneous events can have a significant impact on the pricing of earnings.     

Rock around the clock: An agent-based model of low- and high-frequency trading

We build an agent-based model to study how the interplay between low- and high-frequency trading affects asset price dynamics. Our main goal is to investigate whether high-frequency trading exacerbates market volatility and generates flash crashes. In the model, low-frequency agents adopt trading rules based on chronological time and can switch between fundamentalist and chartist strategies. By contrast, high-frequency traders activation is event-driven and depends on price fluctuations. High-frequency traders use directional strategies to exploit market information produced by low-frequency traders. Monte-Carlo simulations reveal that the model replicates the main stylized facts of financial markets. Furthermore, we find that the presence of high-frequency traders increases market volatility and plays a fundamental role in the generation of flash crashes. The emergence of flash crashes is explained by two salient characteristics of high-frequency traders, i.e., their ability to i. generate high bid-ask spreads and ii. synchronize on the sell side of the limit order book. Finally, we find that higher rates of order cancellation by high-frequency traders increase the incidence of flash crashes but reduce their duration.