Cannibalization Effect Research Articles

The use of GIS tools to support decision-making in the expansion of chain stores

This article deals with a network competitive localization problem in which a firm seeks to determine the location of a new facility, which competes with all the facilities operating in the market, both belonging to the same firm and to the competing firms. In this context, two frequently conflicting objectives are involved: maximization of the total market share captured by the firm and minimization of market share losses for its existing facilities due to being captured by the new facility (cannibalization). We formulate the location problem as a multi-objective optimization model. Some GIS tools that provide some maps representing the market share and the cannibalization effect are proposed. This allows for the visualization of the effects produced by the opening of a new facility in the market and the trade-offs between the objectives. Finally, the advantages of using these tools have been shown by means of an application to a real data case.

An Examination of Cannibalization Effects within the Riverboat Gaming Industry: The Case of Illinois‐Area Casinos

AbstractAs states become increasingly reliant on taxable casino revenues to augment their budgets, questions concerning optimal casino location have entered into policy dialogues across the country. Notably, policy makers have become concerned with the presence and size of so‐called “cannibalization effects” within the casino industry whereby casinos operating within overlapping markets capture one another's business. However, the size, significance, and underlying mechanics of these effects have received very little attention in the academic literature. Using a unique data panel for the Illinois region that spans over a decade, this paper develops a working framework for identifying the presence of intra‐industry cannibalization effects for the riverboat gaming industry. Evidence suggests cannibalization effects do indeed exist and are largely a function of new casino development, not the expansion of pre‐existing casinos. These effects also attenuate rather quickly with distance.

A first step towards improving copepod cultivation using modelling: the effects of density, crowding, cannibalism, tank design and strain selection on copepod egg production yields

Copepods are the optimal live feed for hatcheries and improvement of cultivation techniques, to provide a constant food source, is crucial for the expansion of the industry. However, studies based on experimental work and real observations can be labour intensive and expensive. A simple model was developed based on the well-known life history traits of Acartia tonsa to describe batch cultures and their productivity. Model results were compared to observations from real cultures. For maximizing egg production yields, the optimal stocking density of copepods should be adapted to the design (depth) of the culture tanks. At high densities, stress due to encountering conspecifics, as well as cannibalism of eggs by adults, limits egg production yields. Using this model, the potential selection efficacy of copepod strains was also evaluated in order to increase production yields. Selecting larger copepods increases the egg production per litre of culture, but decreases the optimal stocking density and the range of densities at which egg production yield is high, and vice-versa. Selecting copepods that are less affected by stress due to conspecifics only affect production yields at very high adult densities. However, selecting copepods with a high Specific Growth Rate (SGR), or improving their SGR, was found to be an alternative which did not affect the optimal cultivation densities but improved egg production yields.

High-density nursery culture of recently-settled blue king crabs (Paralithodes platypus): Comparisons to red king crabs (Paralithodes camtschaticus)

Stock enhancement through the release of cultured juveniles has been suggested as a possible recovery tool for depleted red (Paralithodes camtschaticus) and blue (Paralithodes platypus) king crab populations in Alaska, USA. Considerable progress has been made in the past decade in red king crab culture technology, but similar technologies are less developed for blue king crabs. As part of a stock enhancement feasibility study, hatchery-raised blue king crab juveniles were cultured from larvae of ovigerous females collected off Saint Matthew Island, Alaska. Juvenile instars were then cultured in indoor nursery containers for 42days at stocking densities of 500, 1000, 2000, 4000, and 6000crabsm−2 starting at metamorphosis to the first instar stage (C1). At day 42, survival was above 90% at all the densities, but had a slightly decreasing trend that ranged from 96% at 500crabsm−2 to 90% at 6000crabsm−2. The numbers of crabs cannibalized increased with density, but the overall increase in crab biomass offset the negative effects of cannibalism. Survival rates and biomass production for the first 42days post-settlement is much higher for blue king crabs compared to red king crabs reared under identical conditions. The low rate of cannibalism implies that blue king crabs are well suited for large-scale hatchery culture. Our results suggest that these two closely related crab species can be reared at different stocking densities immediately flowing settlement and that high densities will maximize hatchery efficiency for blue king crabs. Future studies should investigate longer term nursery culture, beyond 42days, to refine protocols for extended blue king crab rearing. Improving nursery techniques will boost the productivity and financial viability of a large-scale stock enhancement program.

Search Quality and Revenue Cannibalization by Competing Search Engines

Consumers are attracted by high‐quality search results. Search engines, though, essentially compete against themselves because consumers are induced to substitute away from advertisement links when their organic counterparts are of high quality. I characterize the effect of such revenue cannibalization upon equilibrium quality when search engines compete for clicks. Cannibalization provides an incentive for quality degradation, engendering low‐quality equilibria—even when provision is costless. When consumers exhibit loyalty there is a ceiling above which result quality cannot rise, regardless of what the maximum feasible quality happens to be. Seemingly procompetitive developments may exert downward pressure on equilibrium quality.

New Model Introductions, Cannibalization and Market Stealing: Evidence from Shopbot Data

Incremental innovation plays an important role in competitive conduct in high-tech industries. This paper explores the impact of new model introduction by employing a nested logit specification to investigate the determination of market shares across and within submarkets for a panel of 336 digital cameras. Our results confirm the existence of pronounced life cycle effects and the existence of statistically significant market stealing and cannibalization effects, particularly associated with the introduction of a technologically superior entrant into the model's market segment. The paper reveals significant differences in market outcomes, in both elasticity and response to entry, across submarkets.

Multi‐Product Quality Competition: Impact of Resource Constraints

We study a multi‐product firm with limited capacity where the products are vertically (quality) differentiated and the customer base is heterogeneous in their valuation of quality. While the demand structure creates opportunities through proliferation, the firm should avoid cannibalization between its own products. Moreover, the oligopolistic market structure puts competitive pressure and limits the firm's market share. On the other hand, the firm has limited resources that cause a supply‐side fight for adequate and profitable production. We explicitly characterize the conditions where each force dominates. Our focus is on understanding how capacity constraints and competition affect a firm's product‐mix decisions. We find that considering capacity constraints could significantly change traditional insights (that ignore capacity) related to product‐line design and the role of competition therein. In particular, we show that when the resources are limited, the firm should offer only the product that has the highest margin per unit capacity. We find that this product could be the diametrically opposite product suggested by the existing literature. In addition, we show that for intermediate capacity levels, whereas the margin per unit capacity effect dominates in a less competitive market, proliferation and cannibalization effects dominate in a more competitive market.

Stabilizing Effect of Cannibalism in a Two Stages Population Model

In this paper we build a prey-predator model with discrete weight structure for the predator. This model will conserve the number of individuals and the biomass and both growth and reproduction of the predator will depend on the food ingested. Moreover the model allows cannibalism which means that the predator can eat the prey but also other predators. We will focus on a simple version with two weight classes or stage (larvae and adults) and present some general mathematical results. In the last part, we will assume that the dynamics of the prey is fast compared to the predator's one to go further in the results and eventually conclude that under some conditions, cannibalism can stabilize the system: more precisely, an unstable equilibrium without cannibalism will become almost globally stable with some cannibalism. Some numerical simulations are done to illustrate this result.

Stage-structured cannibalism with delay in maturation and harvesting of an adult predator.

A three-dimensional stage-structured predator-prey model is proposed and analyzed to study the effect of predation and cannibalism of the organisms at the highest trophic level with non-constant harvesting. Time lag in maturation of the predator is introduced in the system and conditions for local asymptotic stability of steady states are derived. The length of the delay preserving the stability is also estimated. Moreover, it is shown that the system undergoes a supercritical Hopf bifurcation when the maturation time lag crosses a certain critical value. Computer simulations have been carried out to illustrate various analytical results.

Impacts of enemy-mediated effects and the additivity of interactions in an insect trophic system

In this study, we used data from both experiments and mathematical simulations to analyze the consequences of the interacting effects of intraguild predation (IGP), cannibalism and parasitism occurring in isolation and simultaneously in trophic interactions involving two blowfly species under shared parasitism. We conducted experiments to determine the short-term response of two blowfly species to these interactions with respect to their persistence. A mathematical model was employed to extend the results obtained from these experiments to the long-term consequences of these interactions for the persistence of the blowfly species. Our experimental results revealed that IGP attenuated the strength of the effects of cannibalism and parasitism between blowfly host species, increasing the probability of persistence of both populations. The simulations obtained from the mathematical model indicated that IGP is a key interaction for the long-term dynamics of this system. The presence of different species interacting in a tri-trophic system relaxed the severity of the effects of a particular interaction between two species, changing species abundances and promoting persistence through time. This pattern was related to indirect interactions with a third species, the parasitoid species included in this study.

Using attraction to light to decrease cannibalism and increase fry production in guppy (Poecilia reticulataPeters) hatcheries. I: phototactic reaction and light colour preference

A substantial proportion of newborns are lost in guppy hatcheries to cannibalism by the broodfish although small-mesh baskets, which allow passage to small fry only and provide a predation-free area, are used in breeding tanks. If newborn guppies are attracted by light, illuminating the small-mesh baskets might enhance aggregation of newborns in the mesh basket and thus mitigate cannibalism effect. In this study, light attraction and light colour preference in newborn guppies were investigated. Testing the attraction to white, blue, green and red LED lights revealed attraction to each of these light types in newborns, but no significant attraction in adult females. Both newborns and adult females exhibited reduced mobility under red LED light. In a preference experiment in which all light colours were presented simultaneously, newborns were most attracted to the white light (52.0% of the newborns) and least attracted to the red light and darkness (6.8% and 6.7% of the newborns respectively). These results support the potential efficacy of using white light to attract newborns into the baskets in guppy breeding tanks and reduce cannibalism effects.

Factors influencing sexual cannibalism and its benefit to fecundity and offspring survival in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

Sexual cannibalism is hypothesized to have evolved as a way to obtain a high-quality meal, as an extreme mate choice or as a consequence of female aggressive spillover. Here, we examined underlying factors likely to influence sexual cannibalism in the wolf spider Pardosa pseudoannulata (Bosenberg & Strand, 1906) from China, including mating status, female egg-laid status, female hunger level, female adult age and mate size dimorphism. The results showed that about 10 % of P. pseudoannulata virgin females cannibalized the approaching males before mating and that 28 % of P. pseudoannulata virgin females immediately cannibalized the males after mating. No incidents of sexual cannibalism during copulation were observed. Before mating, previously mated females and starved females tended to engage in significantly higher rates of attacks compared to virgin and well-fed females. Females that had laid egg sacs tended to engage in a significantly higher rate of attacks and sexual cannibalism than virgin females before mating. Regardless of pre- or post-mating, there was a strong positive relationship between mate size dimorphism and the occurrence of sexual cannibalism. We also tested the effects of sexual cannibalism on the fecundity of cannibalistic females and the survival of their offspring. Our results indicated that sexual cannibalism affected positively the offspring survival of cannibalistic females, but not fecundity. Our findings support the hypothesis that sexual cannibalism has evolved as an adaptive component of female foraging strategy and that it benefits offspring survival as a result of paternal investment.

Sibling Rivalry: Estimating Cannibalization Rates for Innovations

Abstract To evaluate the success of a new product, managers need to determine how much of its new demand is due to cannibalizing the company’s other products, rather than drawing from competition or generating primary demand. A new model allows managers to estimate cannibalization effects and to calculate the new product’s net demand, which may be considerably less than its total demand. The new methodology is applied to the introduction of the Lexus RX 300 using detailed car transaction data. This case is especially interesting since the Lexus RX 300 was the first crossover SUV, implying that its demand could come from both the SUV and the Luxury Sedan categories. As Lexus was active in both categories, there was a double cannibalization potential. Indeed, demand is shown to originate from different sources and to vary over time. The results contain valuable insights for evaluating and managing brand extensions.

Community-Level Consequences of Cannibalism

Ecological interactions determine the structure and dynamics of communities and their responses to the environment. Understanding the community-level effects of ecological interactions, such as intra- and interspecifc competition, predation, and cannibalism, is therefore central to ecological theory and ecosystem management. Here, we investigate the community-level consequences of cannibalism in populations with density-dependent maturation and reproduction. We model a stage-structured consumer population with an ontogenetic diet shift to analyze how cannibalism alters the conditions for the invasion and persistence of stage-specific predators and competitors. Our results demonstrate that cannibalistic interactions can facilitate coexistence with other species at both trophic levels. This effect of cannibalism critically depends on the food dependence of the demographic processes. The underlying mechanism is a cannibalism-induced shift in the biomass distribution between the consumer life stages. These findings suggest that cannibalism may alter the structure of ecological communities through its effects on species coexistence.

Intraguild Predation between Lady Beetles and Lacewings: Outcomes and Consequences Vary with Focal Prey and Arena of Interaction

AbstractWe examined reciprocal intraguild predation (IGP) and cannibalism among various combinations of Coleomegilla maculata DeGeer and Chrysoperla cornea Stephens larvae as they developed feeding on greenbugs, Schizaphis graminum Rondani, on sorghum plants in microcosms. Pairs of C. maculata larvae suppressed aphids better than pairs of C. carnea larvae or heterospecific larval pairs and yielded the highest rate of plant survival. IGP by C. carnea larvae occurred mostly in the first instar, whereas C. maculata larvae were more aggressive in later instars. Although C. carnea was the superior intraguild predator, winning 62.7% of contests in microcosms, this value increased to 88.9% when the experiment was repeated in petri dishes without plant material, regardless of whether greenbugs or eggs of Ephestia kuehniella Zeller were offered as focal prey. Provision in petri dishes of the sessile, higher quality prey (Ephestia) as opposed to greenbugs, improved the survival of solitary larvae and delayed cannibalism and IGP until later developmental stages in both species. Larvae of C. maculata that cannibalized took longer to develop and weighed less at pupation, independent of the arena or prey offered. Although larvae of C. carnea did not pay a cost for cannibalism or IGP in microcosms, there were some negative developmental effects of IGP in petri dishes, particularly on the Ephestia diet. These results illustrate how the plant, as a substrate, can mediate the strength of IGP interactions and how the relative suitability of the focal prey can influence both the timing and consequences of cannibalism and IGP.

Quality and Quantity Competition in a Multiproduct Duopoly

This article proposes a Cournot model of two‐stage competition to examine the patterns of vertical product differentiation in a multiproduct duopoly. Firms simultaneously choose the number of products and their qualities at the first stage and compete in quantities at the second stage. We show that when the fixed setup cost of a product is high enough to result in a monopoly outcome, the monopolist always sells a single product. Moreover, in any equilibrium of a multiproduct duopoly, quality differentiation between them will develop into a nonsegmented pattern because each firm desires to avoid a strong effect of cannibalization. The set of equilibria reveals the properties of quality differentiation between multiproduct firms. In a multiproduct duopoly, the profit from a high‐quality product can be lower than that from a low‐quality product. This finding sharply contrasts with the literature on single‐product firms, which finds the high‐quality advantage.

Location models and GIS tools for retail site location

Competitive location models and GIS are combined to build decision-aid tools in a franchise distribution system when a single facility has to be located in a continuous space. Several objectives are involved, which are sometimes in conflict, and a certain equilibrium among these objectives is desirable. Competitive location models are used to represent the interrelationships among decision makers, and GIS tools are designed to provide both a map representing market share and a map showing the cannibalization effect. These tools allow the incorporation of forbidden regions and other restrictions and visualization of the effects produced by the opening of a new facility.

Relicensing as a Secondary Market Strategy

Secondary markets in the information technology industry, where used or refurbished equipment is traded, have been growing steadily. For original equipment manufacturers (OEMs) in this industry, the importance of secondary markets has grown in parallel, not only as a source of revenue, but also because of their impact on these firms' competitive advantage and market strategy. Recent articles in the press have severely criticized some OEMs who are perceived to be actively trying to eliminate the secondary market for their products. Other OEMs have policies that enhance their secondary markets. The goal of this paper is to understand how an OEM's incentives and optimal strategies vis-à-vis the secondary market are shaped contingent on her relative competitive advantage, product characteristics, and consumer preferences. The critical trade-off that we examine is whether the indirect benefit from maintaining an active secondary market (the resale value effect) can outweigh the potentially negative effect of the sales of used products at the expense of new product sales (the cannibalization effect). To that end, we develop a durable good model where the OEM can directly affect the resale value of her product through a relicensing fee charged to the buyer of the refurbished equipment. We analyze the OEM's strategy in both the monopoly and the duopoly cases, characterize the optimal relicensing fee set by the OEM, and draw conclusions on the conditions that favor stimulating or deterring the secondary market. This paper was accepted by Candace A. Yano, operations and supply chain management.

Substitutability between Online Video Platforms and Television

Given the rising popularity of online video platforms in recent years, this study addresses the plausible cannibalization effect of online video platforms on television. It does so by examining the perceived substitutability between online video platforms and television. A national survey revealed differences between online video platforms and television in terms of consumer motivations for video content consumption. Non-users of online video platforms are also more likely than users of online video platforms to perceive online video platforms as a substitute for television.

Ontogenetic constraints and diet shifts in Perch (Perca fluviatilis): mechanisms and consequences for intra‐cohort cannibalism

Summary1. In many populations, sufficient size variation to allow for cannibalism may develop not only among age cohorts but also within them. Here, we used data on resource dynamics, consumer body size distribution and gape size limitation to unravel mechanisms promoting cannibalism within cohorts of young‐of‐the‐year (YOY) perch (Perca fluviatilis).2. Perch are strongly gape limited when feeding on large zooplankton during early ontogeny. As a consequence, only initially large fish were able to shift to feeding on abundant large invertebrates, necessary to sustain fast growth.3. We suggest that a combination of high initial size variation and exclusive access to resources for individuals with an initial size advantage is a prerequisite for the development of a size distribution sufficient for intra‐cohort cannibalism to occur.4. During the time when cannibalism was observed, growth of the largest individuals in YOY perch cohorts was faster than that of smaller individuals. However, the energy gain from cannibalism did not increase growth rate enough to reach a size necessary to feed on more abundant size classes of victims, and therefore, the effect of cannibalism on overall cohort density was minor.5. In addition to a high energy gain from cannibalism allowing for fast growth, strong resource limitation and slow growth rates of small individuals (i.e. potential victims) are a prerequisite not only for the development of intra‐cohort cannibalism but also for its persistence.