credible spatial preemption it is often argued that incumbent firms may deter entry by preemptive investment in new goods we show that these conclusions are reversed when multiproduct incumbentfirms may exit in response to entry once entrants are in an industry an incumbent will often want to withdraw some goods to prevent competition with the entrant from reducing profits on other goods such a reaction makes entry more attractive to a potential entrant the equilibrium industry structure is less likely to be monopolistic as the goods are better substitutes as exit costs are low and as the competition between producers of the same good is more intense

volume and skewness in international equity markets abstract we examine the relation between trading volume and skewness in 11 international stock markets using daily and monthly data from january 1980 to august 2004 we construct single equation and var models of the relation between the first three moments of market returns and trading volumes our results show hitherto unrecognised channels of influence and support the investor heterogeneity approach to explaining return asymmetries

endogenous sequential entry in a spatial model in this paper we simulate a sequential entry of firms in a differentiated industry a la hotelling firms select a product location once for all they are aware of the unique price equilibrium that will take place after entry has occurred and take into account the behaviour of subsequent entrants it is found that early entrants will systematically locate around the centre but in such a way as not to induce later competitors to locate in between them location choices are also investigated as an instrument for entry deterrence which is feasible because of a fixed cost we identify several ranges of fixed cost for which entry is innocently deterred corresponding to a natural monopoly duopoly triopoly entry deterrence is then typically used to stretch the range of fixed cost for which a given number of firms can be sustained deterrence strategies are consistently such that firms locate at more regular intervals

risk return and the three moment capital asset pricing model another look abstract most studies on three moment capital asset pricing models have found a strong and consistent relationship between an asset s returns and its higher statistical moments other studies report results which are opposite to what the theory would suggest this paper re examines the empirical evidence of the three moment capital asset pricing model on 43 randomly selected mutual funds from 1970 1986 the results indicate that trade offs of risks for returns on the selected mutual funds are less than predicted and inconsistent

why do diners tip rule of thumb or valuation of service when diners decide how much to tip is the decision based on social convention or on conscientious appraisal of server productivity previous researchers in economics and social psychology are generally inconclusive on this question a common finding in the literature is that tip size and service quality are unrelated a result usually obtained from ols regressions ols is only appropriate if service quality is exogenous it is argued that service quality is very likely endogenous in any regression of tip size good quality encourages good tips but server expectations of good tips encourage good quality this simultaneity is accounted for by jointly estimating percentage tips and customer rankings of service quality on a sample of 247 diners in a central minnesota restaurant included are explanatory variables consistent with both the social psychology and economic views of tipping in contrast to previous studies it is found that service quality significantly affects tip size and when servers expect hi

the dynamic annihilation of a rational competitive fringe by a low cost dominant firm abstract a low cost dominant firm will drive all competitive fringe firms out of the market if all firms have rational expectations however the dominant firm will not predate price below marginal cost since a dominant firm will not drive out fringe firms if they have myopic expectations it may be in the dominant firm s best interests to inform the fringe the effects of governmental intervention on the optimal path and welfare are presented

contestable markets under uncertainty in this article we present a model of a market which is ex post contestable we show that in a market characterized by uncertainty a firm will face a tradeoff between efficiency and flexibility and generally will make some precommitments to take advantage of ex ante technologies we show that in the face of potential entry the incumbent will increase his precommitments and in so doing will affect the probability of entry the degree of market contestability is therefore endogenously determined by the choice of precommitments the extent to which precommitments will be used to affect entry probabilities is shown to depend on the efficiency of ex ante production adjustment costs and the degree of uncertainty in particular we show that the market becomes more contestable as the relative efficiency of ex post production increases and as market conditions become more uncertain

location choice product proliferation and entry deterrence within a slightly modified version of hotelling s model we reconsider the claim that the threat of entry induces existing firms to produce a larger number of products than they would otherwise we show that entry deterrence although optimal need not be achieved through product proliferation in some cases the incumbent monopolist resorts to an entry deterring strategy based on location choice rather than product proliferation we also show that in some cases the number of products chosen by the incumbent facing the threat of entry is strictly greater than the minimum number required to deter entry

on diversification given asymmetry in returns complete diversification is the rational investment strategy for a risk averse individual in a homogeneous securities market who considers only the first two moments of return observed behavior of market participants however demonstrates that the majority of individual investors hold imperfectly diversified portfolios the purpose of the present study is to examine one potential cause for this behavior which does not rely on imperfection in the capital market specifically we show that given the existence of and investor preference for positive skewness a rational investor may hold an optimal limited number of homogeneous risk assets the relationship between the number of risk assets in a portfolio and the total risk of the portfolio has been examined extensively both theoretically and empirically 7 8 16 the general conclusion from these analyses which are set in a mean variance framework is that adding randomly selected and equally weighted risk assets to a portfolio will reduce total risk without affecting return the implication for risk averse investors in a perfect market is that complete diversification is optimal observed behavior of market participants however demonstrates that the majority of individual investors hold imperfectly diversified portfolios in the wharton survey of 1975 in 4 the median number of stocks held was found to be fewer than 4 with 34 percent of the investors holding no more than 2 stocks the two primary studies providing evidence of the undiversified portfolios of individual investors are blume and friend 3 and blume friend and crockett 5 the former analysis was based on a sample of individual income tax returns from 1971 and indicated that considering only dividend paying stocks 34 15 percent of investors sampled held only one stock 50 51 percent held no more than 2 stocks and only 10 72 percent held 10 or more stocks the latter study which included nondividend paying stocks was based on the federal reserve board s 1962 survey of the financial characteristics of consumers the median number of holdings per household was 2 while the average was 3 41 in both 3 and 5 numerous other measures of diversification were employed with the results confirming the conclusion that individual investors are on average highly undiversified the principal theoretical reasons advanced by the authors of these studies relate to the relaxation of assumptions of the standard capital asset

replicating options with positions in stock and cash in most situations of practical relevance the price behavior of a call option is very similar to a combined position involving the underlying stock and borrowing the call price and the stock price will change in the same direction the effect on the call price of a one dollar change in the stock price however will depend on the current price of the stock the number of shares of stock in the replicating portfolio must equal the slope of the call price curve at that price when the call is deep out of the money i e when the stock price is much lower than the striking price a one dollar change in the stock price has little effect on the call price when the stock price is equal to the striking price a one dollar change in the stock price produces roughly a half dollar change in the call price if the stock price rises until the call is deep in the money a one dollar move in the stock price results in nearly a one dollar move in the call price because the call price behaves this way we must revise

incentives and service quality in the restaurant industry the tipping service puzzle tipping is a significant economic activity tips in the us food industry alone amount to about 42 billion annually that was claimed to improve service quality and increase economic efficiency because it gives incentives to provide excellent service and therefore allows to avoid costly monitoring of workers the article suggests that this common wisdom might be wrong a simple model shows formally that tips can improve service only if they are sensitive enough to service quality empirical evidence suggests that tips are hardly affected by service quality nevertheless rankings of service quality by customers are very high the co existence of these two findings is denoted the tipping service puzzle and several possible explanations for it are offered

investigating the behavior and characteristics of the madrid stock exchange abstract this study examines the efficiency and characteristics of the nine major indexes of the madrid stock exchange from 1941 through 1992 the findings do not support weak form efficiency among the general bank construction investment metal working and chemical indexes results of the utility food and communications index tests are not consistent

on measuring skewness and elongation in common stock return distributions the case of the market index this article is an exploratory investigation of the distributional properties of market index returns using j w tukey s g and h distributions specifically it is shown that over sufficiently long periods of time the distribution of the market index is adequately explained as a skewed elongated g x h distribution estimates of skewness and elongation are developed that are easy to calculate and are robust with respect to outliers functional forms for the appropr iate distributions are provided the findings reported here have implications for understanding skewness and elongation developing appropriate portfolio strategies and devising pricing models incorporating higher moments copyright 1988 by the university of chicago

entry deterrence and the free rider problem the public good aspect of entry prevention is examined in an industry characterized by an established oligopoly facing a potential entrant although incumbent firms act noncooperatively underinvestment in entry deterrence does not occur and in fact incumbents may find themselves in a pareto dominated arrangement in terms of profits by preventing entry

market competition r d and firm profits in asymmetric oligopoly we investigate a cournot model with strategic r d investments wherein efficient low cost firms compete against less efficient high cost firms we findthat an increase in the number of high cost firms can stimulate r d by the low cost firms while it always reduces r d by the high cost firms more importantly this force can be strong enough to compensate for the loss that arises from more intense market competition the low cost firms profits may indeed increase with the number of high cost firms an implication of this result is far reaching as it gives low cost firms an incentive to help rather than harm high cost competitors we relate this implication to a practice known as open knowledge disclosure especially ford s strategy of disclosing its know how publicly and extensively at the beginning of the 20th century

equilibrium number of firms and economic welfare in a spatial price discrimination model abstract we examine welfare implications of the equilibrium number of entering firms in a spatial price discrimination model in contrast to salop salop s 1979 monopolistic competition with outside goods bell journal of economics 10 141 156 the equilibrium number of firms can be either excessive or insufficient from the normative viewpoint

the bright side of having an enemy conventional wisdom suggests that more intense competition will lower firms profits the authors show that this may not hold in a channel setting with exclusive retailers they find that a manufac

deterrence by market sharing a strategic incentive for licensing the potential of an incumbent firm to retain its dominant position in a market is a focal point of the modem theory of industrial organization a recent literature examines this issue for markets in which challengers threaten an incumbent s position by engaging in research for a new technology richard gilbert and david newbery 1982 show that an incumbent firm with a firstmover advantage will preempt potential entrants by inventing a new technology slightly earlier than would its rivals in a stochastic r d therefore its introduction does not alter the decision to research when the pre innovation market is characterized by an incumbent and potential entrants stephen salant 1984 shows that licensing ex post to innovation can alter the research decision as anticipation of the returns from future licensing encourages research by the entrant as a counterpoint to the salant result i find that licensing ex ante to research may discourage further research by the entrant indeed this strategic incentive for licensing may be so strong as to persuade the incumbent as well as the entrant to terminate research activity to isolate this incentive for licensing from the one discussed by salant a simple model is constructed in which licensing of future technologies is not desirable anecdotal evidence suggests that the strategic incentive does lead innovators in some markets to license their technologies examples of this information sharing are prevalent in markets where technological change is rapid in the 1940 s standard oil of new jersey discovered a process for synthetic rubber it traded patent rights on this process for a synthetic oil production process discovered by farben a german rubber company in both the synthetic oil and synthetic rubber markets rival companies were department of economics scarsborough college university of toronto toronto ontario canada m5s lal i thank jon cohen and ron saunders for discussions that inspired this paper i am also grateful to yehuda kotowitz andy mclennan jennifer reinganum ralph winter myma wooders two anonymous referees and seminar participants at the university of toronto for helpful comments on earlier drafts

sequential entry industry structure and welfare in this paper we reexamine the relationship between potential competition industry structure and welfare in a market subject to a sequential entry threat where firms can make quantity commitments and have access to a constant returns technology it is shown that provided entry is not blockaded the incumbent s will either prevent entry or allow all the potential entrants in furthermore actual entry may decrease but social welfare never goes down with more potential entrants nevertheless with a finite number of potential entrants policies which lower the cost of entry need not be beneficial in welfare terms

a note on credible spatial preemption in an entry exit game i investigate how an incumbent firm deters entry by crowding the market even when the incumbent can withdraw its stores in response to entry in a two location model judd 1985 shows such spatial entry deterrence is not credible in contrast i demonstrate spatial preemption can be credibly employed in a circular city model if the incumbent can build its stores on sufficiently many locations and transportation costs are linear

strengthening a weak rival for a fight abstract we provide a new model wherein firms of different productivities survive in an industry despite the threat of entry by high productivity firms we demonstrate that an efficient incumbent has a unilateral incentive to establish a relational contract softening price competition to strengthen its inefficient rival in a war of attrition that emerges post entry and raising the price of the inefficient firm in the acquisition market we show that this equilibrium gives rise to persistent performance differences market compression and stability in the identity of firms in the market moreover the relational contracting equilibrium is facilitated by strong anti trust laws

ladies first a field study of discrimination in coffee shops despite anecdotal and survey evidence suggesting the presence of discrimination against customers in stores restaurants and other small transaction consumer markets few studies exist that identify or quantify the nature of any unequal treatment we provide evidence from a field study of wait times in boston area coffee shops that suggests that female customers wait an average of 20 seconds longer for their orders than do male customers even when controlling for gender differences in orders we find that this differential in wait times is inverse to the proportion of employees who are female and directly related to how busy the coffee shop is at the time of the order this supports the conclusion that the observed differential is driven at least in part by employee animus and or statistical discrimination rather than unobserved heterogeneity in the purchasing behaviour of female customers

rational entry into risky markets with negative expected returns the role of biased misestimation of profit potential abstract we extend the theory of negative long run profits in risky industries by incorporating a negatively skewed profit distribution rational behavior with incomplete information is introduced by allowing economic agents to know the median rather than the mean rate of return we compare this to the case involving postdecision bolstering where entrants choose to discount available information on the industry profit distribution monte carlo experiments are tailored to the experience of the u s home building industry

skewness persistence with optimal portfolio selection abstract existing studies have found that ex post stock returns are positively skewed but such skewness is only persistent for individual stocks not for portfolios this implies that the ex post knowledge of skewness may not be useful in ex ante portfolio selection however the portfolios in these studies are not optimally formed because preferences for skewness are not taken into consideration when forming these portfolios it is more meaningful to see if the positive skewness would persist in optimally formed mean variance skewness efficient portfolios using stocks from both japanese and us markets and a bootstrap method we find that the portfolios optimally formed by using a polynomial goal programming method which considers preference for skewness greatly enhances skewness persistence over time our results are robust across both japanese and us stocks however the skewness persistence is stronger for portfolios formed with monthly data than that with weekly data these findings have practical implications to investors with skewness preferences

weak entrants are welcome abstract this paper investigates the decision problem of an incumbent firm confronted by both a weak and strong entrant in a differentiated market suppose that the incumbent can deter entry of the weak firm but cannot deter entry of the strong firm by itself then the incumbent may allow entry of the weak firm and use it to alter the strong firm s entry decision the present paper formalizes this idea and it sheds new light on the fact that domestic firms are sometimes able to block strong foreign firms after trade liberalization the idea also explains why a dominant firm lets fringe firms be in the market

on estimating skewness in stock returns in recent years skewness has become a much discussed factor in financial research and many studies models involve the skewness of various financial variables this paper i points out the universal neglect in the finance literature of skewness sampling error and its significant consequences ii presents a simple approach for roughly constructing a confidence interval for skewness estimated from lognormal populations iii points out directions of further research for developing a comprehensive approach for estimating skewness reliably

exclusionary vertical contracts with multiple entrants abstract this paper constructs a model of anticompetitive exclusive dealing in the presence of multiple entrants unlike the single entrant model in previous literature an entrant competes not only with the incumbent to deal with buyers but also with other entrants the competition among entrants then serves as a commitment such that low wholesale prices are offered to buyers when they deviate from exclusive contracts we argue that this commitment effect becomes a barrier to exclusive dealing and that the results differ drastically from the predictions of the single entrant framework

do people tip because of psychological or strategic motivations an empirical analysis of restaurant tipping one of the most interesting and central questions about tipping is why people tip the two major potential reasons are strategic behaviour aimed to ensure good future service and social psychological motivations data on tipping behaviour suggests that there is no positive effect of patronage frequency on the sensitivity of tips to service quality this implies that people tip only because of social and psychological motivations and not because of strategic reasons and future service considerations

skewness persistence in common stock returns recent empirical studies have found ex post common stock returns to be consistently positively skewed the frequency of positive skewness in this study is found to be relatively stable over varying time periods from 1961 to 1980 however the skewness of individual stocks and portfolios of stocks does not persist across different time periods positively skewed equity portfolios in one period are not likely to be positively skewed in the next time period past positively skewed returns do not predict future positively skewed returns

the bootstrap approach for testing skewness persistence this study presents a new methodology for testing changes in skewness between time periods or samples using the bootstrap method a monte carlo simulation experiment was conducted to compare the effectiveness of the bootstrap method with the method suggested by lau wingender and lau 1989 to test skewness persistence the results show the bootstrap method to be more powerful than the other method the bootstrap method was also used to determine the persistence of skewness in stock returns the results show that in a large percentage of stocks skewness persists over time

strategic wholesale pricing in a supply chain with a potential entrant this paper develops an adverse selection model for a two stage supply chain with one supplier one retailer and a potential outside entrant supplier who makes a partially substitutable product the work is different from most research on entry deterrence that only considers a single stage model our main interest is to investigate how the incumbent supplier can strategically maximize her profit by a wholesale pricing policy when facing the potential entrant we focus on a model where the entrant supplier will sell her product through the same incumbent retailer we derive the optimal decisions for each player and study the comparative statics of the equilibrium to investigate how the supply chain structure may affect the deterrence strategy of the incumbent supplier we also consider three alternative models with different channel structures when both suppliers sell their products directly when the entrant has another independent retailer and when the entrant sells her product directly through the comparison we find that the existence of the common downstream retailer often enhances the deterring motivation of the incumbent supplier

portfolio selection and skewness evidence from international stock markets abstract this paper finds that the returns of the world s 14 major stock markets are not normally distributed and that the correlation matrix of these stock markets was stable during the january 1988 december 1993 time period polynomial goal programming in which investor preferences for skewness can be incorporated is utilized to determine the optimal portfolio consisting of the choices of 14 international stock indexes the empirical findings suggest that the incorporation of skewness into an investor s portfolio decision causes a major change in the construction of the optimal portfolio the evidence also indicate that investors trade expected return of the portfolio for skewness

can price competition dominate market segmentation this note analyses duopoly competition in a two stage location price game while allowing each firm to establish a couple of outlets both the circle and the line model of spatial competition are considered our main result is clear cut in equilibrium neither firm will take up the opportunity of opening two stores this is a warning that market segmentation i e competition from multiple outlets might not be attractive at all because it entails more intense price competition

cleaning house the impact of information technology monitoring on employee theft and productivity this paper examines how firm investments in technology based employee monitoring impact both misconduct and productivity we use unique and detailed theft and sales data from 392 restaurant locations from five firms that adopt a theft monitoring information technology it product we use difference in differences models with staggered adoption dates to estimate the treatment effect of it monitoring on theft and productivity we find significant treatment effects in reduced theft and improved productivity that appear to be primarily driven by changed worker behavior rather than worker turnover we examine four mechanisms that may drive this productivity result economic and cognitive multitasking fairness based motivation and perceived increases of general oversight the observed productivity results represent substantial financial benefits to both firms and the legitimate tip based earnings of workers our results suggest that employee misconduct is not solely a function of individual differences in ethics or morality but can also be influenced by managerial policies that can benefit both firms and employees this paper was accepted by serguei netessine operations management

selecting a portfolio with skewness recent evidence from us european and latin american equity markets abstract polynomial goal programming in which investor preferences for skewness can be incorporated is utilized to determine the optimal portfolio from latin american us and european capital markets the empirical findings suggest that the incorporation of skewness into an investor s portfolio decision causes a major change in the resultant optimal portfolio the empirical evidence indicates that investors do trade expected return of the portfolio for skewness