Exit Choice Research Articles

Simulating dynamics of adaptive exit-choice changing in crowd evacuations: Model implementation and behavioural interpretations

A crucial aspect of simulating crowds’ evacuation processes is that humans can dynamically revisit and change their decisions. While a relatively great deal of attention has been paid by recent studies to modelling directional decision making, the ‘exit decision changing (or decision adaptation)’ phenomenon has been largely overlooked. Here, we quantitatively investigate (I) how important is to include a decision changing module in evacuation simulation models, and (II) whether decision changing is beneficial to evacuation processes. We propose and implement a parsimonious discrete-choice model of decision changing. The model embodies the most influential factors that make an evacuee revise and adapt their choice of exit. This includes the effects of ‘relative queue-size imbalance at exits’, ‘visibility of exits’, ‘social influence’ and ‘inertia (for maintaining initial decisions)’. Results showed that, the inclusion of the decision changing module made a very substantial difference in enhancing the accuracy of the simulation outputs. Simulating exit choices as one-off decisions strictly limited the degree of match that could be achieved between the simulated and experimental outputs (in terms of replicating the observed exit shares and evacuation times) (question I). Further analyses also revealed that an intermediate degree of decision changing is a strategy that most benefits the system. By contrast, the extreme decision-changing strategies (i.e. “no change” and “too many changes”) were found to be suboptimal. Also, while we have observed, in our other studies, that imitative (or the so-called herd-type) behaviour in ‘exit choices’ is invariably detrimental to evacuation systems, here, we observed that when it comes to ‘adapting exit choices’, a moderate degree of imitation (or follow-the-peer) tendency makes the system more efficient (question II).

Entrepreneurial Finance and Economic Growth: A Canadian Overview

Equity capital plays an important and growing role in connecting financial resources to investment opportunities in a highly productive manner. Exchange-listed companies, IPOs, venture capital and private equity are all complementary investment avenues. Each plays a vital role that allows companies more efficient access to capital for improving productivity, boosting long-term growth and innovation, and creating better jobs. On this dimension, Canada enjoys an enviable position. Despite these positive factors, Canada’s ranking compared to that of other major economies on key dimensions of competitiveness and drivers of sustainable economic growth has been declining. In 2009-10, Canada ranked ninth on the Global Competitiveness Index; in 2018, it had fallen to twelfth place. More worrisome for the future is that Canada’s lacklustre performance in areas known to be significant contributors to productivity, competitiveness and sustainable growth is pervasive across industries and regions. Although the Canadian financial industry cannot be held responsible for all the shortcomings in Canada’s performance, there is no escaping that a disconnect seems to exist between the generally favourable assessment of the effectiveness and strength of the Canadian financial industry and the overall competitiveness of the Canadian economy in the short and long run. One potential explanation has to do with the median size of exits in Canada, which is almost an order of magnitude smaller than in the United States. Moreover, institutional equity investors often engage in sales to foreign firms rather than IPOs. One powerful disincentive to exit through public markets is federal government tax policies that discriminate against and penalize Canadian innovative and high-growth companies that “go public.” In addition to correcting these counterproductive biases, serious consideration should be given to adopting a tax measure similar to the US Small Business Jobs Act of 2010, which provides for full exemption from federal taxation of capital gains realized on the sale of the shares of certain small businesses. There is empirical evidence that the exemption has had a significantly positive effect in the US. Serious consideration should also be given to reducing the capital gains tax on shares issued by qualified SMEs when they list on a Canadian stock exchange and are held by individual investors for a reasonable period of time, since evidence suggests that capital gains taxes influence the underpricing of IPOs. The adoption of such a tax measure applicable to exits by an IPO or upon listing the shares on a Canadian stock exchange would help establish a more neutral playground for the choice of exits, which, to a large extent, is the crux of the matter.

A dynamic estimation method for aircraft emergency evacuation based on cellular automata

To reduce the time of aircraft passenger evacuation in an unplanned emergency and improve passenger safety, this article proposed a dynamic estimation method of an aircraft emergency evacuation process; optimal performance statistics can be estimated efficiently. Then, the emergency guiding model is established based on the cellular automata theory. In this model, multiple factors are considered, such as seat pitch, exit width, and occupant behavior. A total of six categories (target exit choice, movement direction selection, movement speed calculation, behavior representation, crew operation, and exit modeling) and 24 evacuation regulations are included. Two kinds of civil aircraft with 90 seats and 149 seats were tested individually using the proposed model and a traditional model. The total evacuation time can be reduced by more than 5%, and optimal performance statistics can be reduced by more than 30%. The results indicate that with this model, more lives can be saved in the case of an emergency.

To Merge, Sell, or Liquidate? Socioemotional Wealth, Family Control, and the Choice of Business Exit

We take the perspective that considering the affective motives of dominant owners is essential to understanding business exit. Drawing on a refinement of behavioral agency theory, we argue that family-controlled firms are less likely than non-family-controlled firms to exit and tend to endure increased financial distress to avoid losses to the family’s socioemotional wealth (SEW) embodied in the firm. Yet, when confronted with different exit options and when performance heuristics suggest that exit is unavoidable, family firms are more likely to exit via merger, which we argue saves some SEW, although it is less satisfactory financially. In contrast, nonfamily firms are more likely to exit via sale or dissolution, options that are more prone to offer higher financial returns than mergers. Family and nonfamily firms thus show different orders of exit options. We find support for these arguments in a longitudinal matched sample of privately held firms.

Simulation of Pedestrian Evacuation in University Canteen Based on Cellular Automata

In this study, we firstly build up an exit choice model to describe the pedestrians' exit choice behavior in a specific place, i.e., university canteens. The pedestrians are assumed to minimize their evacuation time in choosing exits by explicitly considering the estimated evacuation time and effects of pedestrians' destinations. In addition, the behavior of food tray return is also captured in the proposed route choice model for pedestrians. Fusing the exit choice model and the route choice model into a cellular automata (CA)-based pedestrian simulation model, we simulate the pedestrian evacuation process in university canteen and the results illustrate the effectiveness of the modeling framework in terms of describing the evacuation process in university canteens. Specifically, destination is identified as a key influence factor for pedestrian evacuation, and pedestrians tend to select the exit that is closer to their destinations. If it is required to return the food tray to designated spots before leaving the canteen, the evacuation efficiency is significantly reduced. The simulation result can also assist in determining the optimal number of tray-return spots if maximum evacuation efficient is to be achieved. In presence of the specific parameter settings and canteen layout in the case study example, it is recommended to deploy four tray-return spots in the university canteen.

Brexit: Re‐opening Ireland's ‘English Question’

AbstractThe outcome of the UK referendum of June 2016 on the question of EU membership had and will continue to have a profound impact on Ireland, its membership of the EU and on British‐Irish relations, given the UK's choice of exit over voice. This paper analyses Brexit from the perspective of the island of Ireland. It adopts three analytic lenses: first, Brexit is analysed from a domestic Irish perspective; second, the negotiations between the EU and the UK and Ireland's position in these negotiations is analysed from a dynamic temporal perspective; third, the paper focuses on the all island dimension of Brexit and its implications for the Irish border. The Irish border will continue to play a pivotal role in the Brexit negotiations and will remain an unsettled issue long after the UK's exit.

Technological Disruptiveness and the Evolution of IPOs and Sell-Outs

This paper examines startups’ positioning within technological cycles. We use patent text to measure whether innovation pertains to a technological area that is rapidly evolving or stable. We show that innovation in rapidly evolving areas (i.e., early in the cycle) substitute for existing technologies, whereas innovation in stable areas (i.e., later in the cycle) complement them. Our new measure is distinct from existing characterizations of innovation and is economically important. We find that startups in rapidly evolving areas tend to exit via IPO, thus remaining independent, consistent with technological substitution. In contrast, startups in stable areas tend to sell-out, consistent with technological complementarity and synergies.

An Empirical Analysis of VCPE Exits: Evidence from Indian Infrastructure Sector

The choice of exit between IPO and M&A is an inevitable decision faced by venture capital and private equity (VCPE) investors. This article examines the exits of VCPE funds from their portfolio companies in the Indian infrastructure sector. The analysis covers the influence of VCPE investors’ characteristics in terms of stages of financing and origin of funds on their choice of exit route. The article also explores the influence of syndication and board representation devices as controlling mechanisms on the exit route. The findings suggest the type of exit can be well predicted by the size of the investment, the duration of investment, and the extent of syndication. This article highlights the growing importance of VCPE for the infrastructure sector in India and makes the case that more exit options should be facilitated in order to promote further investment in the sector.

Evaluation of evacuation methods in underground metro stations

The evacuation process is a key part of the emergency response strategy to manage and control a variety of emergency situations or disasters. Many regulations and standards have been put into effect in order to ensure both the proper workplace design and the efficient evacuation procedure. This is something that is passing on to the underground space design, a critical urban infrastructure with special needs and requirements. The paper analyses the evacuation process and its performance in an underground metro station that is under development in Greece, as part of the Thessaloniki metro project. This is achieved by following the guidelines set by the NFPA design guidelines, in terms of users load and concentration, travel speed and maximum allowable time to reach a point of safety. In addition to that - and beyond static hand calculation numbers - the evacuation process is simulated through the use of the Pathfinder software package, under a number of scenarios regarding occupants’ speed and exit route availability. Both methods are evaluated over several parameters such as results efficiency and type, scenario management. Results show that the major advantage of computer modelling evacuation is the ability to assess conditions and parameters such as worst case scenario, critical occupants’ average speed and the influence of exit choice in evacuation time.This allows for the overall assessment of the critical conditions that might occur during the evacuation and the overall safety of the underground space users.

Developing a database for pedestrians' earthquake emergency evacuation in indoor scenarios.

With the booming development of evacuation simulation software, developing an extensive database in indoor scenarios for evacuation models is imperative. In this paper, we conduct a qualitative and quantitative analysis of the collected videotapes and aim to provide a complete and unitary database of pedestrians’ earthquake emergency response behaviors in indoor scenarios, including human-environment interactions. Using the qualitative analysis method, we extract keyword groups and keywords that code the response modes of pedestrians and construct a general decision flowchart using chronological organization. Using the quantitative analysis method, we analyze data on the delay time, evacuation speed, evacuation route and emergency exit choices. Furthermore, we study the effect of classroom layout on emergency evacuation. The database for indoor scenarios provides reliable input parameters and allows the construction of real and effective constraints for use in software and mathematical models. The database can also be used to validate the accuracy of evacuation models.

The effects of information and hazard on evacuee behavior in virtual reality

Many contextual factors can influence evacuees' choice of egress route during an emergency. Anxiety caused by the emergency situation may lead to suboptimal choices, resulting in slower evacuation and greater risk of injury or death. The present pilot study tests the influence of hazard level (presence of visible fire and smoke) and information about an obstacle (delivered verbally or through signage) on evacuees' anxiety levels and choice of egress route in a virtual reality (VR) simulation of a fire evacuation with multiple possible exits. Physiological measures were recorded and used to validate the efficacy of VR in inducing anxiety germane to the situation of interest. Consistent with our expectations, providing information about the obstacle was shown to decrease total evacuation time. Contrary to our predictions, it did not significantly impact evacuees' choice of exit. Information also had a marginally significant effect on participants' self-reported anxiety. Providing more targeted information may further reduce anxiety and evacuation time. More generally, VR appears well-suited to assessing individual and psychological factors in evacuations.

Exit choice in an emergency evacuation scenario is influenced by exit familiarity and neighbor behavior

‘Movement to the familiar' has been reported during evacuation incidents but has not yet been studied in controlled experiments. We investigate effects of exit familiarity and egress behavior of other pedestrians on exit choice in an ambulatory virtual environment. Participants walked into a virtual museum through a ‘familiar’ door and were asked to evacuate when a fire alarm sounded as they normally would in the real world. They were significantly more likely to exit through the familiar door than through a second available exit. This effect was greater when virtual neighbors also left by the familiar door and was reduced when neighbors left by the unfamiliar door; this social influence was stronger with two neighbors than with one. The results show that exit familiarity and neighbor behavior influence evacuation behavior, and that social influence increases with the number of neighbors. The findings have implications for modeling pedestrian evacuation and improving evacuation procedures.

Exit Choice Behavior of Pedestrians Involving Individuals with Disabilities During Building Evacuations

Pedestrian evacuation studies are critical in obtaining information about evacuation scenarios and in preparing to face the challenges of actual evacuations. Studies have examined evacuation policies, exit choice modeling, and evacuation curve analysis. Some studies have addressed the evacuation behavior of individuals with disabilities (IWDs), although this important aspect of evacuation seems to be missing from modeling of the exit choice in many studies. In modeling of the exit choice for evacuation, many studies have been found to be based on the stated preference survey method, where evacuees are asked to choose an exit based on descriptions, without an actual experiment taking place. This study focuses on the discrete choice model of the exit choice in the room for both IWDs and individuals without disabilities (IWODs). The results demonstrate that the presence of IWDs in the group plays a crucial role in the exit choice for all evacuees. The results demonstrate that there are significant differences in exit choice between IWDs and IWODs. Current evacuation policies have been found to be more focused on visual signs, while this study demonstrates that these visual signs are of little importance to individuals with visual disabilities.

A social force model for the crowd evacuation in a terrorist attack

A social force model is developed in this paper to study the crowd evacuation when a terrorist attack occurs in the public place. The persons in the model are divided into two groups—terrorists and pedestrians. On one hand, each terrorist chooses the nearest pedestrian as the target. Once the distance between him and his target is small enough, the terrorist will launch attacks on his target and the target will be killed with a certain probability. On the other hand, each pedestrian tries to avoid the terrorists and reach the exits. An emergency exit choice strategy which emphasizes the security risk factor is developed for pedestrians. The main simulation results are summarized as follows. First, the number of deaths in the terrorist attack increases with the number of terrorists and with the density of pedestrians. If the number of exits decreases, the death toll will become more sensitive to the change of the density of pedestrians. Second, adding the number of exits can significantly reduce casualties. Third, more pedestrians will be killed and the evacuation speed will be reduced if terrorists start the attack from the positions of the exits. Fourth, the emergency exit choice strategy has an advantage over the ordinary exit choice strategy in daily life for reducing casualties. The more unbalanced the terrorists’ initial distribution around the exits is, the more noticeable this advantage will be. Fifth, the number of deaths will decrease obviously if at least half of the exits are available and safe. Our study is valuable for developing an effective evacuation scheme to reduce casualties in a terrorist attack.

Incorporating intelligence for typical evacuation under the threat of fire spreading

Having to escape from a moving threat, such as a fire, is a tremendously frightening event during an evacuation. Evacuees’ decisions in such circumstances could be better made with an awareness of fire dynamics and potential risks. Rationality is a human factor which has an essential role in accomplishing typical evacuation in emergency situations. In this article, the authors propose a rule-based exit choice model in which the simulated individuals are provided with the assessment of exit’s disutility and decision-making capability for selecting and reselecting exits due to the evacuation dynamics. The model allows for the simulation of systematic crowd distribution at exits up until the end of the evacuation process, thereby accomplishing a more efficient evacuation. For further refinement, we allow the individuals to predict the dynamics of the fire spreading and involve its effect on the individuals’ assessment. We consider a precaution time for each individual as an essential parameter to guarantee safety from the fire spreading or equivalent risk. Simulations are performed and the discussion of fast and safe decision-making are introduced.

The Choice of Exit: Influence of Private Equity Investors and Buyout Entry

The choice of exit method is an inevitable decision faced by entrepreneurs and private equity (PE) investors. The existing literature addresses four categories of factors which influence this choice of exit method between initial public offering (IPO) and acquisition: industry-related factors, market-timing variables, deal-specific factors and demand-for-funds factors. We extend the literature by introducing a new category of factors, ‘PE investor characteristics’, and test if this category has a significant effect on the choice of exit method. We also test if the type of entry has an influence on the exit method. We find that PE investor characteristics play an important role in the choice of exit method. The existence of a large syndicate of PE investors in the same firm increases the probability of an IPO exit, but the presence of a foreign PE investor reduces this probability. Moreover, unlike in developed markets, the cost of debt does not affect the choice of exit method in India. We further consider specific exit methods such as strategic sale, financial sale and buyback and find consistent results. We find that in buyout transactions, the probability of an IPO exit is less than that of a strategic sale. Finally, we present a unique finding that the probability of a buyback as opposed to an IPO is higher if a firm is in the real estate sector.

The Impact of JOBS Act on M&As

Do changes in the IPO regulatory environment affect private firms’ exit choices, bargaining abilities, and valuations? Using the JOBS Act as an exogenous shock to the exit decisions among private firms, we observe that their valuations as M&A targets increase by 36% after the Act, negatively affecting acquirer wealth gains. These results are more prominent for VC-backed targets. We also find that stock (cash) deals decrease (increase) for private firms after the Act. Our results are robust to endogeneity concerns, alternative measures, placebo tests, and other robustness tests.

A Cellular Automaton Model for Exit Selection Behavior Simulation during Evacuation Processes

Abstract Exit selection behavior is important for evacuation processes and safe facility design. Pedestrians’ ability to select an exit route is affected by many factors, and will also impact on evacuation efficiency. It should not be neglected when modeling evacuation. In the case of asymmetric exits and distribution of pedestrians, an important issue is how to identify a pedestrian’s target when performing simulations. However, this has not been well investigated, especially in discrete models. In this regard, we tend to investigate pedestrian exit choice behavior by integrating the least effort algorithm with a cellular automaton model. The distance to exits and crowd density around exits are involved. Simulations are conducted in a two-exit room. Evacuation time in scenarios where there are some special distributions of pedestrians is compared with that in scenarios where pedestrians are randomly distributed. The influence of the weighted value of the distance to exits or crowd density around exits on evacuation time is also studied. Useful suggestions are provided. The effect of locations of exits on evacuation time and the cumulative number of egress pedestrians are further investigated. Results demonstrate that two exits located in different walls, especially in symmetrical walls, are helpful in evacuation processes. This result is in line with that in other references. It is hoped that this work will be helpful in improving evacuation rules of discrete models in multi-exit situations.

Incorporating Intelligence into Exit Choice Model for Typical Evacuation

Integrating an exit choice model into a microscopic crowd dynamics model is an essential approach for obtaining more efficient evacuation model. We describe various aspects of decision-making capability of an existing rule-based exit choice model for evacuation processes. In simulations, however, the simulated evacuees clogging at exits have behaved non-intelligently, namely they do not give up their exits for better ones for safer egress. We refine the model to endow the individuals with the ability to leave their exits due to dynamic changes by modifying the model of their excitement resulted from the source of panic. This facilitates the approximately equal crowd size at exits for being until the end of the evacuation process, and thereby the model accomplishes more optimal evacuation. For further intelligence, we introduce the prediction factor that enables higher probability of equally distributing evacuees at exits. A simulation to validate the contribution is performed, and the results are analyzed and compared with the original model.

Pedestrian evacuation behavior analysis and simulation in multi-exits case

Considering the process of pedestrian evacuation as pedestrian walking freely from current position to exit and queuing at the exit, estimated evacuation time model for single pedestrian is established. Based on estimated evacuation time and shortest distance, pedestrian exit choice model is established considering pedestrian preference. Pedestrian exit choice model is added into pedestrian simulation model which is built based on cellular automata. Pedestrian evacuation behavior in multi-exits case is simulated. The simulations indicate that pedestrian evacuation model built in our work describes the pedestrian evacuation behavior well.