sequential formation of coalitions in games with externalities and fixed payoff division this paper analyzes a sequential game of coalition formation when the division of the coalitional surplus is fixed and the payoffs are defined relative to the whole coalition structure gains from cooperation are represented by a valuation which maps coalition structures into payoff vectors i show that any core stable coalition structure can be attained as a stationary perfect equilibrium of the game if stationary perfect equilibria may fail to exist in general games a simple condition is provided under which they exist in symmetric games furthermore symmetric stationary perfect equilibria of symmetric games generate a coalition structure which is generically unique up to a permutation of the players a general method for the characterization of equilibria in symmetric games is proposed and applied to the formation of cartels in oligopolies and coalitions in symmetric majority games journal of economic literatureclassification numbers c78 c71 1996 academic press inc

current publication lags in economics journals phe economics profession depends to a large degree upon its scholarly journals to disseminate the results and applications of its recently completed research the journal of economic literature is in fact evidence of that dependence much of the contents of each issue is devoted to an indexing of the current articles to facilitate both access to primary sources and quick cross referencing with related material but how recent are the results reported in the current literature how long does it usually take for a piece of research to evolve from a submitted manuscript to a published article to my knowledge only one study has confronted this question directly and it was published nearly 15 years ago in that study robert coe and irwin weinstock 1967 p 40 reported an average lag between submission and publication of 250 days 8 2 months for articles published in 1966 what has happened since there are no formal surveys to support the suspicion but there is evidence to suggest that the lags have actually increased some journals have begun to charge submission fees ostensibly to reduce the number of manuscripts they must review a plethora of specialized journals have emerged to provide new outlets for specialized papers and to relieve some of the burden from the traditional journals of more general scope one new journal economics letters has been founded completely in response to the lag problem it publishes short papers as quickly as possible in an effort to distribute at least the thrust of current research without a prolonged waiting period all of these responses to long lags lead to one question how severe are the current lags between submission and publication this brief note will report on the results of a survey that can begin to assess the current magnitude of the lag problem the major components of that problem and the success of the various efforts to alleviate it information about the lags involved in the 40 most recently published articles in each journal was solicited from the editors of 66 journals whose contents are routinely recorded in the jel twenty editors responded directly to the request and their reports formed the foundation of this study seven other journals were also in

is it worthwhile to pay referees there are puzzles in refereeing scholarly articles why are referees willing to review a paper without payment and is it worthwhile to pay referees in order to raise the review rate two interesting results are found in this article first when reviewing services are driven by reciprocity the equilibrium participation of referees may exhibit the so called self fulfilling feature second the optimal payment may not be zero if the referee receives the benefit of reputation gained by refereeing an article in particular this article will show that those journals whose status quo review rate is lower tend to pay reviewers more while journals whose status quo review rate is higher do not find it worthwhile to pay referees enough this result implies that in order to raise its quality a journal with a low review rate is more likely to adopt a strategy to increase pay and attract a critical mass of referees

endogenous formation of coalitions with composite goods abstract we construct a model of endogenous formation of coalitions when three goods are necessary for a composite good and composite goods are substitutes for each other this analysis extends economides and salop s journal of industrial economics xl 1992 105 model of composite goods where two goods are necessary we analyze the welfare implications of coalition structure and investigate which coalition structure leads to the highest social welfare the paper investigates whether the most desirable coalition structure represents an equilibrium and provides a sufficient condition for the socially efficient coalition structure to be a stable nash coalition structure

does paying referees expedite reviews results of a natural experiment a natural experiment in an economics field journal afforded time series observations on payments to referees for on time reviews the natural experiment yielded 15 months worth of data with no payments and about two subsequent years of data with payments using refereeand manuscript specific measures as covariates hazard models were used to gauge the effects of payments on individual referee s review times all models indicate statistically significant reductions in review times owing to referee payments reductions in review times translate into significant reductions in first response time frt median frt was reduced from 90 to 70 days a 22 reduction in the presence of payments with payments only 1 of the frts exceeded six months without payments 16 of the frts exceeded six months

a theory of endogenous coalition structures consider an environment with widespread externalities and suppose that bind ing agreements can be written we study coalition formation in such a setting our analysis proceeds by defining on a partition function an extensive form bargaining game we establish the existence of a stationary subgame perfect equilibrium for such a game our main results are concerned with the characterization of equilib rium coalition structures we develop an algorithm that generates under certain conditions an equilibrium coalition structure our characterization results are especially sharp for symmetric partition functions in particular we provide a uniqueness theorem and apply our results to a cournot oligopoly journal of economic literature classification numbers c71 c72 c78 d62 q 1999 academic press

modelling oil price volatility with structural breaks in this paper we provide two main innovations i we analyze oil prices of two prominent markets namely west texas intermediate wti and brent using the two recently developed tests by narayan and popp 2010 and liu and narayan 2010 both of which allow for two structural breaks in the data series and ii the latter method is modified to include both symmetric and asymmetric volatility models we identify two structural breaks that occur in 1990 and 2008 which coincidentally correspond to the iraqi kuwait conflict and the global financial crisis respectively we find evidence of persistence and leverage effects in the oil price volatility while further extensions can be pursued the consideration of asymmetric effects as well as structural breaks should not be jettisoned when modelling oil price volatility

the review process in economics is it too fast rewards for publications in good economics journals are very high and submission fees and other monetary costs associated with submitting an existing manuscript are low consequently the editorial delay especially the first response time the time until the first editorial decision by postponing monetary rewards to publication constitutes the major submission cost from the author s perspective reducing the delay will induce many additional submissions of low quality papers to good journals increasing significantly the workload of editors and referees moreover the rejection rate will increase and cause papers to be rejected more times before publication offsetting at least some of the shorter first response times as a result the efforts of many editors to reduce the editorial delay although attracting more submissions to their journals may have adverse effects from a social perspective and the optimal delay might be longer than the current average of four months

investigating dynamic conditional correlation between crude oil and fuels in non linear framework the financial and economic role of structural breaks abstract to understand the crude oil volatility has been a challenge the non linear behavior the skewed and leptokurtic returns the presence of structural breaks and the constant political instability in suppliers countries evidence the necessity of complex models to capture the market volatility at the same time crude oil is the raw material for several fuels such as jet fuel gasoline diesel and others having a strong influence over their prices thus this study aims to verify the presence of structural breaks in the volatility series and in the correlations between wti return and the returns of gasoline kerosene jet fuel diesel heating oil propane and natural gas to reach this objective we identified which model presents the best fit to estimate the conditional mean between wti and each fuel and we used a copula dcc garch model to estimate the conditional volatility avoiding the frequently unrealistic presumptions of normality our main results indicate the necessity of a different model for each analyzed pair and the presence of at least one structural break in the conditional volatility and in the correlation between wti and each fuel usually preceded by a structural break in wti return series

stable coalition structures with open membership and asymmetric firms i study games of coalition formation with open membership where firms form associations in order to decrease their costs before competing on the market according to previous analyses only the grand coalition forms at the nash equilibrium of such games i show that this result hinges on the assumption of symmetric firms i therefore introduce asymmetric firms in a game where only two associations can form i demonstrate that there exists a coalition proof nash equilibrium coalition structure in this game and that when the equilibrium involves two associations all the members of an association have a higher taste for this association than all nonmembers do journal of economic literature classification numbers c70 c72 l13

evolution of social norms with heterogeneous preferences a general model and an application to the academic review process abstract the article presents a model of social norm evolution that suggests how the increase in optimal and actual first response times frt of economics journals can be related when the optimal frt and the norm about how much time refereeing should take increase it seems that the existence of a norm increases the average refereeing time the model suggests the surprising result that this is not necessarily true i also discuss applications of the model in other contexts differences in the optimal frt between disciplines the effects of the frt on the tenure process and strategic behavior of referees

competition and integration among complements and network market structure this article analyzes the competition and integration among complementary products that can be combined to create composite goods or systems the model generalizes the cournot duopoly complements model to the case in which there are multiple brands of compatible components it analyzes equilibrium prices for a variety of organizational and market structures that differ in their degree of competition and integration the model applies to a variety of product networks including automatic teller machines real estate multiple listing services and airlines crs as well as to nonnetwork markets of compatible components such as computer cpus and peripherals hardware and software and long distance and local telephone services copyright 1992 by blackwell publishing ltd

the slowdown in first response times of economics journals can it be beneficial the first response time henceforth frt of economics journals has increased over the last four decades from 1 2 months to 3 6 months the optimal frt however is not zero because the frt deters submission of mediocre papers to good journals and consequently saves valuable time of referees and editors the change in the actual frt is in the same direction as the change in the optimal frt which has increased because of the availability of research on the internet prior to publication and because the costs of refereeing a paper have increased

scholarships citations and salaries economic rewards in economics while substantial attention has been paid to the determinants of academics earnings 5 7 8 14 15 this literature has by implication suggested that the mere fact of having spent more time in the profession and the publication of more scholarly articles and books are the major determinants of salary differences our purpose here is to introduce a new determinant the quality of one s scholarly research measured by the frequency of references to that work as an additional objective measure of productivity we expect that this proxy for the extent of a scholar s influence on the work of other researchers is rewarded by the market in addition to giving a more complete picture of the determination of salaries in academic labor markets our approach should be useful in establishing a better framework for the evaluation of issues of discrimination in such markets than has been presented before 2 9

the copula garch model of conditional dependencies an international stock market application abstract modeling the dependency between stock market returns is a difficult task when returns follow a complicated dynamics when returns are non normal it is often simply impossible to specify the multivariate distribution relating two or more return series in this context we propose a new methodology based on copula functions which consists in estimating first the univariate distributions and then the joining distribution in such a context the dependency parameter can easily be rendered conditional and time varying we apply this methodology to the daily returns of four major stock markets our results suggest that conditional dependency depends on past realizations for european market pairs only for these markets dependency is found to be more widely affected when returns move in the same direction than when they move in opposite directions modeling the dynamics of the dependency parameter also suggests that dependency is higher and more persistent between european stock markets

volatility transmission and volatility impulse response functions in crude oil markets abstract using daily data from july 2005 to february 2011 for wti dubai and brent futures contracts we employ a var bekk model to investigate crude oil markets integration on the second moment we also quantify the size and persistence of these connections through the analysis of volatility impulse response functions virf for two historical shocks namely the 2008 financial crisis and the bp deepwater horizon oil spill we observe that brent and dubai crude are highly responsive to market shocks whereas wti crude shows the least responsiveness of the three benchmarks which creates questions about its predominance as a benchmark crude oil furthermore we fit the density of the virf at different forecast horizons these fitted distributions are asymmetric showing that the probability of observing a large impact of a shock is lower while the probability of a relatively smaller impact is much higher finally we simulate the virf for a given probability of a random shock the virf shows that only a large shock derived from a smaller probability will result in an increase in expected conditional volatilities these results provide useful insights into the volatility transmission mechanism in crude oil markets and their associated risk estimation and may have significant implications for various market participants and regulators

have oil and gas prices got separated abstract this paper applies vector error correction models that show that oil and natural gas prices decoupled around 2009 before 2009 us and uk gas prices had a long term equilibrium with crude prices to which gas prices always reverted after exogenous shocks both us and uk gas prices adjusted to the crude oil price individually and departure from the equilibrium gas price on one continent resulted in a similar departure on the other after an exogenous shock the adjustment between us and uk gas prices took approximately 20 weeks on average and the convergence was mediated mainly by crude oil with a necessary condition that arbitrage across the atlantic was possible after 2009 however the uk gas price has remained integrated with oil price but the us gas price decoupled from crude oil price and the european gas price as the atlantic arbitrage has halted the oversupply from shale gas production has not been mitigated by north american export as there has been no liquefying and export capacity

an analysis of publication lags in econometrics this note describes the lengthening in publication lags for econometric papers in seven journals since 1986 and briefly considers ways of shortening them

the slowdown of the economics publishing process over the last three decades there has been a dramatic slowdown of the publication process at top economics journals a substantial part is due to journals requiring more extensive revisions various explanations are considered democratization of the review process increases in the complexity of papers growth of the profession and cost and benefit arguments changes in the profession are examined using time series data connections between these changes and the slowdown are examined using paper level data there is evidence for some explanations but most of the slowdown remains unexplained changes may reflect evolving social norms

flexible parametric estimation of duration and competing risk models in this paper we specify and estimate a flexible parametric proportional hazards model the model specification is flexibly parametric in the sense that the baseline hazard is non parametric while the effect of the covariates takes a particular functional form we also add parametric heterogeneity to the underlying hazard model specification we specify a flexible parametric proportional competing risks model which permits unrestricted correlation among the risks unemployment duration data are then analysed using the flexible parametric duration and competing risks specifications we find an important effect arising from the exhaustion of unemployment insurance and significantly different hazards for the two types of risks new jobs and recalls

endogenous formation of coalitions the formation of coalitions is a fundamental problem in game theory by a coalition is meant a group of players e g economic or political agents which decide to act together as one unit relative to the rest of the players this includes the instances of syndicates unions cartels blocks political parties parliamentary coalitions etc we would like to emphasize that forming a coalition does not eliminate the individual players as decision makers in all interactions with the other players coalition members act as one unit it may be useful to think of a representative agent taking their place 2 however this arrangement will continue only as long as each player finds it desirable to act this way further bargaining occurs among the members of each coalition on how to divide what they obtained together thus the existence of coalitions implies that the interactions among the players will be conducted on two levels first among the coalitions and second within each coalition most of the existing models in economics and game theory assume that the coalition structure is given exogenously instead we try here to obtain it as an endogenous outcome of our model namely we want to be able to predict which coalitions will in fact form in each given situation 3 our theory combines two kinds of game theoretic concepts value and stability the basic idea is first to evaluate the players prospects in the various coalition structures and then based on these values to find which ones are stable we will call this value coalition structure value or cs value for short the reason we are considering coalition structures i e partitions of the set of players into disjoint coalitions rather than just coalitions is that in general players may find it to their advantage to join forces in some situations and to act separately in others all depending on the way the other participants are organized this implies that both the value and the stability concepts should depend on the entire coalition structure the cs value we analyze in this paper was first developed by owen 7

how do crude oil prices co move a copula approach abstract this paper examines the dependence structure between crude oil benchmark prices using copulas by considering several copula models with different conditional dependence structures and time varying dependence parameters we find evidence of significant symmetric upper and lower tail dependence between crude oil prices these findings suggest that crude oil prices are linked with the same intensity during bull and bear markets thus supporting the hypothesis that the oil market is one great pool in contrast with the hypothesis that states that the oil market is regionalized our findings on crude oil price co movements also have implications for risk management hedging strategies and asset pricing