have trading rule profits in the currency markets declined over time abstract previous studies have reported mixed results regarding the success of technical trading rules in currency markets abnormal returns were observed in many studies using data up to the mid 1980s while more recent studies generally report less success for technical trading rules this paper tests whether moving average trading rule profits have declined over the period from 1971 to 2000 if so previous profits may represent a temporary inefficiency that has since been eliminated in the currency markets the hypothesis is tested using 18 exchange rate series over a longer time period than in previous studies rules are optimized for successive 5 year in sample periods from 1971 to 1995 and tested over subsequent 5 year out of sample periods results show that risk adjusted trading rule profits have declined over time from an average of over 3 in the late 1970s and early 1980s to about zero in the 1990s thus market inefficiencies reported in previous studies may have been only temporary inefficiencies

the demand for energy cross country evidence using the florida model abstract income and own price elasticities of demand for energy for 51 countries in 1980 are presented based on pooled estimates from an 11 good demand system estimated with the florida model results indicate income elasticities of demand for energy are significantly larger than unitary for all countries and own price elasticities of demand for energy range between 0 8 and 1 0

the demand for energy evidence from a cross country demand system abstract some new evidence on the income own price elasticities of demand for energy consumption by consumers is presented estimates are derived from a complete system of cross country demand equations with energy being one of the commodities considered

the growth of interorganizational systems in the presence of network externalities we develop a model of network growth in the presence of network externalities for the case where a buyer initiates an interorganizational system with its suppliers in our two stage model suppliers joining the network in the first stage can gain economic benefit from increased market share or higher price for the primary product suppliers encounter negative externalities since the economic benefit accruing to participating suppliers is less for increasingly larger networks in the first stage the buyer may experience initial supplier adoption of the network followed by a stalling problem due to negative externalities in order to overcome this stalling problem the buyer may find it optimal to subsidize some suppliers costs to join the network in the second stage we characterize the buyer s optimal second stage subsidy policy and show the conditions under which the buyer will find it optimal to offer a subsidy if the suppliers have some positive ex ante expectation of a second stage subsidy the growth of the network will be retarded in the first stage resulting in suboptimal profits for the buyer

technical trading rules in the european monetary system abstract using genetic programming we find trading rules that generate significant excess returns for three of four ems exchange rates over the out of sample period 1986 1996 permitting the rules to use information about the interest rate differential proved to be important the reduction in volatility resulting from the imposition of a narrower band may reduce trading rule profitability our results cannot be duplicated by commonly used moving average rules filter rules or by two rules designed to exploit known features of target zone rates there is no evidence that the excess returns are compensation for bearing systematic risk

the statistical properties of daily foreign exchange rates 1974 1983 abstract this paper examines the statistical properties of daily rates of change of five foreign currencies from 1974 to 1983 the main purpose is to discriminate between two competing explanations for the observed heavy tails of the distribution that the data are independently drawn from a heavy tail distribution which remains fixed over time and that the data come from distributions which vary over time evidence point to the rejection of the first hypothesis further investigations show that the rejection can be attributed to changing means and variances in the data which can be described by a simple statistical model

bargaining and sharing innovative knowledge we consider the problem of bargaining over the disclosure of interimresearch knowledge between two participants in an r d race for an ultimate patentable invention licence fee schedules that are functions of the amount of knowledge disclosed by the leading to the laggingagent are examined for their abilities to attain efficient outcomes andvarying shares of the surplus arising from disclosure in hersequential offers bargaining games the uninformed buyer is able to elicitfull disclosures without sharing the incremental surplus with any type ofthe licensor and thus do as well as a perfectly informed and discriminatingknowledge licensee

market efficiency of brazilian exchange rate evidence from variance ratio statistics and technical trading rules abstract this study utilizes the variance ratio test to examine the behavior of brazilian exchange rate we show that adjustments for multiple tests and a bootstrap methodology must be employed in order to avoid size distortions we propose a block bootstrap scheme and show that it has much nicer properties than the traditional chow denning chow k v denning k c 1993 a simple multiple variance ratio test journal of econometrics 58 3 385 401 multiple variance ratio tests overall the method proposed in the paper provides evidence refuting the random walk behavior for the brazilian exchange rate for long investment horizon but consistent with the random walk hypothesis for short run horizon additionally we also test for the predictive power of variable moving average vma and trading range break trb technical rules and find evidence of forecasting ability for these rules nonetheless the excess return that can be obtained from such rules is not significant suggesting that such predictability is not economically significant

performance of technical analysis in growth and small cap segments of the us equity market abstract a large universe of technical trading rules applied to a set of technology industry and small cap sector portfolios over the 1995 2010 period yields superior predictability after adjusting for data snooping bias in the first half of the sample period and delivers statistically significant profits for a number of portfolios when the transaction cost is assumed to be of small to moderate size technical analysis is not able to outperform the buy and hold approach for any portfolio in the set in the second half of the sample period the finding that the short term return predictability becomes much weaker in the more recent period suggests that the underlying segments of the equity market have become more efficient over time the fact that mechanical trading strategies have been futile after adjusting for data snooping bias for two samples of portfolios where technical analysis is most anticipated to succeed suggests that it is unlikely to have delivered abnormal returns in any other segment of the domestic equity market in the last decade

measuring the distance between relative price vectors of different countries abstract a simple measure is developed for the distance between relative price vectors it is applied to cross country data the procedure also provides a justification for the use of geometric mean prices in cross country demand analysis

the significance of technical trading rule profits in the foreign exchange market a bootstrap approach abstract in this paper we present new evidence on the profitability and statistical significance of technical trading rules in the foreign exchange market we utilize a new data base currency futures contracts for the period 1976 1990 and we implement a new testing procedure based on bootstrap methodology our results suggest that simple technical trading rules have very often led to profits that are highly unusual splitting the entire sample period into three 5 year periods reveals that on average the profitability of some trading rules declined in the latest period although profits remained positive on average and significant in many cases jel f31 f47 g15

possibility of relicensing and patent protection abstract we examine the effects of patent protection paying attention to its role of prohibiting relicensing we focus on two questions first whether does the innovator have an incentive of licensing the concealable easily kept secret if not licensed innovation in the case where patent protection is absent second what effects does patent protection have upon the innovator s payoff and the consumers welfare principal findings include the following in the case of nondrastic innovations in the sense of arrow the innovator has an incentive of licensing even without patent protection patent protection generally benefits the innovator but may cause damage to the consumers for large innovations for drastic innovations patent protection has no influence on licensing licensing never takes place regardless of whether it is provided or not

lessons from the evolution of foreign exchange trading strategies abstract the adaptive markets hypothesis posits that trading strategies evolve as traders adapt their behavior to changing circumstances this paper studies the evolution of trading strategies for a hypothetical trader who chooses portfolios from foreign exchange forex technical rules in major and emerging markets the carry trade and us equities the results show that a backtesting procedure to choose optimal portfolios improves upon the performance of nonadaptive rules we also find that forex trading alone dramatically outperforms the s p 500 with much larger sharpe ratios over the whole sample but there is little gain to coordinating forex and equity strategies which explains why practitioners consider these tools separately forex trading returns dip significantly in the 1990s but recover by the end of the decade and have been markedly superior to an equity position since 1998 overall trading rule returns still exist in forex markets with substantial stability in the types of rules though they have migrated to emerging markets to a considerable degree

an information good market with symmetrical externalities in 3 the author investigated how an information good is supplied from its owner to users through trades in a case where all the traders are located at geographically separated points and thus a transmission of the good implies certain costs and moreover its external effects are negligibly small in general however information goods possess negative external effects as seen from the following suppose a firm possessing a new technology gains a profit by monopolistically utilizing it once this technology is known to and used by other firms the firm can no longer enjoy its monopolistic position and might incur a significant loss of profit the aim of this paper is to analyze how a concealable information good with external effects is diffused from its monopolistic owner to demanders through trades generally information goods have their own peculiar properties among them we suppose in this paper the following typical ones the first one is a possibility of free replication namely each trader can replicate the good as many times as he wants without any cost immediately after he obtains it each replica is supposed to be exactly the same as the original good the second one is an indivisibility which implies that each trader gains a benefit just from one unit of the good the third one is an irreversibility in trading the good in the case of trading ordinary goods it would be possible for a buyer to return the good to a seller by cancelling the trade for information goods however this would not be possible since a buyer may replicate it immediately after he purchases because of free replication namely a seller must refuse a buyer s proposal to return it since a buyer might already have its replica the fourth one is a negative external effect mentioned above namely a benefit brought by the good is affected by how the good is possessed among other traders and if some trader newly gets it then the benefit for each possessor is decreased throughout this paper we further assume that costs for transmitting the good are negligibly small a new process for producing chemical products a new computer program and so on are information goods which we have in mind for further description of information goods refer to 1 2 and 5 here we remark that in the case of trading such an information good it might occur from free replication that once each demander owns the good he will

electronic b2b marketplaces with different ownership structures this paper analyzes electronic marketplaces with different ownership structures biased marketplaces and neutral marketplaces biased marketplaces can be either buyer owned or supplier owned whereas neutral marketplaces are owned by independent third parties we develop a single period model with fulfilled expectations equilibrium the buyers experience positive network effects that are a function of the number of suppliers and the suppliers receive similar positive network effects depending on the number of buyers we develop a general model with atomistic buyers and suppliers we find that biased marketplaces set prices to induce greater participation demand from both buyers and suppliers compared to a neutral marketplace this counterintuitive result can be understood in the context of the positive cross network effects experienced by buyers and suppliers and the added benefit to the owner of a biased marketplace from participating in the marketplace biased marketplaces also provide greater social welfare compared to neutral marketplaces

do euro exchange rates follow a martingale some out of sample evidence abstract traditional autocorrelation and variance ratio tests are based on serial uncorrelatedness rather than martingale difference as such they do not capture potential nonlinearity in mean which could lead to misleading inferences in favor of the martingale hypothesis this paper employs various parametric and nonparametric nonlinear models as well as several model comparison criteria to examine the potential martingale behavior of euro exchange rates in the context of out of sample forecasts the overall evidence indicates that while martingale behavior cannot be rejected for euro exchange rates with major currencies such as the japanese yen british pound and us dollar there is nonlinear predictability in terms of economic criteria with respect to several smaller currencies

communication networks externalities and the price of information information goods or information for short play an essential role in modern economies we consider a trading framework where information has some idiosyncratic value for each consumer exerts externalities and can be freely replicated and transmitted through links in a communication network prices paid for information are determined via the asymmetric nash bargaining solution with endogenous disagreement points this decentralized approach leads to unique prices and payoffs in any exogenous network we use these payoffs to find connection structures that emerge under different externality regimes in pre trade network formation stage an application to citation graphs results in eigenvector like measures of intellectual influence

testing for market timing ability abstract in this paper we examine the henriksson merton test of market timing and its potential usefulness in evaluating investment advice the paper proposes a natural extension of the test that is valid under more general assumptions about the distribution of asset returns we show that the henriksson merton test and its more general counterpart are special cases of standard tests of market rationality and efficiency both tests are applied to a group of foreign exchange advisory services

beating the foreign exchange market filter rule profits found in foreign exchange markets in the early days of the current managed float persist in later periods as shown by statistical tests developed and implemented here the test is consistent with but independent of a wide variety of asset pricing models the profits found cannot be explained by risk if risk premia are constant over time inclusion of the home foreign interest rate differential in computing profits has little effect on the comparison of filter returns to those of buy and hold in the early years of the generalized managed floating that began in march 1973 filter rule profits in excess of buy and hold were found for many countries logue sweeney and willett 18 dooley and shafer 6 cornell and dietrich 5 it was unclear however whether such profits indicated inefficiencies first it was not clear that risk was adequately handled in such tests and often risk was ignored second there was no evidence such profits would be available postsample and third there was no statistical test of the significance of these profits this paper uses the logic of risk return tradeoffs to analyze the role of risk in such tests and illustrates the logic in a discussion using the sharpe lintner capital asset pricing model capm although a breeden consumption based capm a merton intertemporal capm or an arbitrage pricing model apm could easily be used the paper develops a test of statistical significance appropriate to foreign exchange markets section i analyzing the rate of return on foreign exchange speculation less the foreign domestic interest rate differential the test explicitly assumes that risk premia are constant over the sample the excess rates of return observable in using filters in going from a risk free dollar asset to a risk free deutsche mark dm asset persist into the 1980 s section ii and this is true even when taking account of transactions costs it turns out that these results for the dm case do not depend very much on the interestrate differential but primarily on exchange rate behavior this is useful to know because it is often quite difficult to find matching interest rate data of high quality for a sample of nine other currencies using only exchange rates section iii shows that the excess returns made in the first 610 days of the float persist in the next 1 220 days into the 1980 s dooley and shafer 7 find similar persistence in experiments that do not use buy and hold and have no significance tests when filter rule profits have been found in spot exchange markets it has often been argued that the profits are due to risk this paper uses the capm to analyze rates of return both to buy and hold and to filter strategies it turns out that the claremont mckenna college and claremont graduate school arthur d warga douglas joines and thomas d willett offered helpful comments and ning ning koo provided research assistance

waiting to imitate on the dynamic pricing of knowledge we study the problem of an inventor who brings to the market an innovation that can be legally imitated imitators may enter the market by imitating the innovation at a cost or by buying from the inventor the knowledge necessary to reproduce and use the invention the possibility of contracting dramatically affects the need for patent protection our results show that i imitators wait to enter the market and the inventor becomes a temporary monopolist ii the inventor sells knowledge through contracts that allow resale by the imitators and iii under certain conditions the inventor s payoff increases with the number of imitators

patent competition rent dissipation and the persistence of monopoly the role of research budgets abstract the paper investigates how patent rights can contribute to the persistence of monopoly patent competition is modelled as a dollar auction game between two firms incumbent and entrant any bid expenditure on r d in the game constitutes sunk cost whose total amount is constrained by fixed research budgets the explicit solution subgame perfect equilibrium determines who wins the patent and how the winning expenditures depend on order of play and budgets of firms the entrant can win if he moves first and has the higher budget rent may or may not be dissipated by the competition

licensing information goods abstract a significant amount of research on patent licensing and the diffusion of knowledge is organized around static frameworks of analysis patent holders however may face a dynamic problem namely the intertemporal consistency problem of the durable goods monopolist that is induced by durability on the demand side licensing practices such as exclusive licensing contracts and most favored customer clauses allow patentees to solve or mitigate this dynamic consistency problem there are situations however where these practices are not possible either due to the nature of the patent the case of information goods or due to compulsory patenting laws we study the effects of the intertemporal consistency problem on patent licensing in these situations relative to the existing literature we obtain the following main results i all of the firms that remain in the industry will be using the innovation ii royalty licensing may be superior to fixed fee or auction licensing from the licensor s point of view iii social welfare and consumer surplus may be lower than when the patent holder can commit not to make additional sales iv even for non drastic innovations the price of the good that is produced may be lower than the competitive price corresponding to the initial situation before the innovation was discovered

on the short term predictability of exchange rates a bvar time varying parameters approach abstract in this paper we propose a bayesian vector autoregressive model with time varying parameters bvar tvp to examine the short term predictability of exchange rates an important contribution of the paper is the application of the bvar tvp model for the first time to daily data using information from financial markets another contribution is the production of forecasts in real time at the very short horizon of one trading day ahead typically used by traders and investors in financial markets we employ financial criteria and recently developed statistical tests to assess the exchange rate predictability we find that the bvar tvp model outperforms the random walk for all exchange rates these forecast gains are due primarily to the time variation of coefficients and secondly to information from other financial markets it is shown that international investors could have made statistically significant excess profits if they had followed an inter day trading strategy based on the buy sell signals generated by the model s one day ahead exchange rate forecasts even after allowing for transaction costs and risk factors

trading rule profits in european currency spot cross rates abstract the moving average ma trading rule is applied to six european spot cross rates jy bp dm bp jy dm sf dm sf bp and jy sf to see if opportunities for profitable trading exist the results suggest that ma trading rules are marginally profitable only for the jy dm and the jy sf cross rates while trading rules are not profitable for the other four cross rates bootstrapping and out of sample tests provide similar results examination of subsamples characterized by central bank intervention do not produce different results computation of box pierce statistics adjusted for heteroscedasticity show that daily returns for all six cross rates are serially uncorrelated overall the results suggests that cross rates are sufficiently transparent to eliminate ma trading rule profit

information transparency of business to business electronic markets a game theoretic analysis the abundance of transaction data available on the internet tends to make information more transparent in electronic marketplaces in such a transparent environment it becomes easier for suppliers to obtain information that may allow them to infer their rivals costs is this good news or bad news in this study we focus on theinformational effects of business to business b2b exchanges and explore firms incentives to join a b2b exchange that provides an online platform for information transmission we then study the equilibria by developing a game theoretic model under asymmetric information we examine whether the incentives to join a b2b exchange would be different under different competition modes quantity and price different information structures and by varying the nature of the products substitutes and complements our results challenge the information transparency hypothesis i e open sharing of information in electronic markets is beneficial to all participating firms in contrast to the popular belief we show that information transparency could be a double edged sword the individual rationality of participation in the online exchange reflects the tradeoff between information transparency and data confidentiality this may have important implications for the microstructure design e g data access rules of b2b electronic marketplaces

preemptive patenting and the persistence of monopoly this article takes a different tack and inquires whether institutions such as the patent system create opportunities for firms with monopoly power to maintain their monopoly power the results apply to other situations such as brand identification spatial location and capacity expansion which share the characteristic that early or preemptive actions may lower the returns to potential competitors

central bank intervention and trading rule profits in foreign exchange markets abstract moving average trading rules are utilized in both futures and spot foreign currency markets to show that significant positive profits can be earned in four of five currencies examined the results are consistent for both in sample and forward simulation tests regression results demonstrate that central bank intervention is strongly associated with the profitability of trading returns for the three major currencies dm yen and pound and partially explains returns for the sf and cd consistent with conjectures in previous studies that news concerning intervention tends to be revealed over weekends we find that moving average trading rule returns are significantly positive on fridays and mondays and not significantly different from zero in the middle of the week

asymmetric stationarity in national stock market indices an mtar analysis a procedure is developed using a momentum threshold autoregressive model and asymmetric stationarity tests designed to identify periods of asymmetric stationary divergences from nonstationary paths in time series and is applied to major national stock indices the results reveal the existence of asymmetric stationary periods in each of these indices these results suggest an explanation for the counterintuitive positive forecasting results of technical traders for various time periods we explore this possibility further by using a representative moving average technical trading strategy and find significantly different results higher returns when information from the procedure is incorporated into a trading rule

do central banks lose on foreign exchange intervention a review article abstract estimates of central bank intervention losses or profits vary widely some estimates find substantial losses others profits in most cases estimated profits are not risk adjusted and risk adjustment can have large effects furthermore profit estimates involve variables integrated of order one and because of this test statistics may have nonstandard distributions few studies take this into account estimates of risk adjusted profits for the us fed and the swedish riksbank with allowances for possible nonstandard distributions suggest that neither made losses and might have made significant profits

resale proofness and coalition proof nash equilibria abstract this paper studies in detail the notion of resale proofness proposed by nakayama quintas and muto it is shown that in an information trading game with one initial owner of information the following are attained as equilibrium outcomes of the game the perfectly coalition proof nash equilibria due to bernheim peleg and whinston if a set of informed agents is resale proof information never diffuses further the initial owner shares his information with a set of demanders such that the resulting set of informed agents forms one of the minimal resale proof sets and the initial owner gains the whole surplus produced by the information sharing

determining firm level it investments to facilitate value chain activities should spillovers accruing to value chain members be incorporated abstract in recent years the relationship between intermediaries in a value chain has undergone significant changes in which information technology it has played a critical role of importance is the formation of alliances between channel members and the effect of it investments on these evolving relationships a critical aspect of a firm s it investment is that it not only provides gains for the investing firm but also creates positive spillovers for value chain members these spillovers are attributable to the fact that firm level it investments result in the automation and or reengineering of internal processes downstream in this paper we address the issue as to how a firm should determine its investment in an it system which is primarily designed to facilitate value chain activities under the assumptions of perfect information in terms of potential gains for value chain members from this it investment and the fact that each member may need to be guaranteed some minimum gain i e a reservation utility to adopt the it we model the it investment decision under two alternative strategies the first strategy referred to as the myopic strategy is where the firm simply makes the it investment decision by maximizing its own gains and ignoring those of the value chain under an alternative strategy referred to as the global strategy the firm decides to make the it investment decision by simultaneously maximizing not only its own gains but also the gains accruing to the entire value chain in this case the firm could make a sub optimum decision regarding the it investment from its own perspective however under the latter strategy the firm could also structure a simultaneous one time charge for each value chain member which could compensate for this sub optimum decision after modeling both these strategies we then proceed to characterize conditions under which each strategy is the preferred choice for the firm through an illustration of our framework we show that the global strategy dominates the myopic strategy in a number of situations

the measurement of income and price dispersion in cross country demand analysis abstract measures are formulated for the dispersion of real income and relative prices across countries they are applied to 30 countries in 1975 for 10 groups of consumer goods

electronic data interchange competitive externalities and strategic implementation policies electronic data interchange edi is an emerging type of standardized inter organizational information system we analyze the impact of edi on the upstream suppliers competitive position in a simple two level hierarchical market structure where the buyer faces a linear demand curve and the competing heterogeneous suppliers have an upward sloping marginal cost function we show that a suppliers adoption of edi can generate positive externalities for the buyer and negative or competitive externalities for other suppliers as a result the buyer provides a price premium to those suppliers who adopt edi and increases their sales volume and market share moreover when the benefits that the buyer can derive from implementing edi are substantial and the suppliers edi adoption costs are high it may be in the buyer s best interest to subsidize the suppliers so as to encourage them to adopt edi instead of mandating them to do so regardless of whether the buyer employs a mandatory or a subsidizing policy the buyer and the end consumers may be the only ones who gain from this new technology consequently a partial adoption by the supplier base may be optimal for the buyer when the suppliers adoption costs are sufficiently high we also show that while edi reduces the transaction costs of the buyer the upstream market tends to become more concentrated as a result of increased cost differentials these results provide one economic explanation of the fact that many companies have actually reduced their supplier base after implementing edi despite a significant reduction in their market transaction costs

income elasticities at different price vectors abstract cross country data are used to evaluate the income elasticities of the demand for ten broad groups of goods at two different price vectors the observed prices of separate countries and the geometric means of these prices across all countries the major effect is on the income elasticity of the demand for food using observed rather than geometric mean prices results in lower elasticity values for the more affluent countries

a decentralized model of information pricing in networks we propose a recursive method of pricing an information good in a network of holders and demanders of this good the prices are determined via a unique equilibrium outcome in a sequence of bilateral bargaining games that are played by connected agents if the information is a homogenous non depreciating good without network effects we derive explicit formulae which elucidate the role of the link pattern among the players particularly we find out that the equilibrium price is intimately related to the existence of cycles in the network it is zero if a cycle covers the trading pair and it is proportional to the direct and indirect utility that the good generates otherwise

model free evaluation of directional predictability in foreign exchange markets we examine directional predictability in foreign exchange markets using a model free statistical evaluation procedure based on a sample of foreign exchange spot rates and futures prices in six major currencies we document strong evidence that the directions of foreign exchange returns are predictable not only by the past history of foreign exchange returns but also the past history of interest rate differentials suggesting that the latter can be a useful predictor of the directions of future foreign exchange rates this evidence becomes stronger when the direction of larger changes is considered we further document that despite the weak conditional mean dynamics of foreign exchange returns directional predictability can be explained by strong dependence derived from higher order conditional moments such as the volatility skewness and kurtosis of past foreign exchange returns moreover the conditional mean dynamics of interest rate differentials contributes significantly to directional predictability we also examine the co movements between two foreign exchange rates particularly the co movements of joint large changes there exists strong evidence that the directions of joint changes are predictable using past foreign exchange returns and interest rate differentials furthermore both individual currency returns and interest rate differentials are also useful in predicting the directions of joint changes several sources can explain this directional predictability of joint changes including the level and volatility of underlying currency returns copyright 2007 john wiley sons ltd

world product and income international comparisons of real gross product the volume reports on the third phase of the united nations international comparison project icp the main results provide comparisons of real gross domestic product gdp per capita for thirty four countries in 1975 quantity and price comparisons are given also for personal consumption capital formation and public consumption and further subdivisions of final expenditures on gdp are estimated

naive trading rules in financial markets and wiener kolmogorov prediction theory a study of technical analysis this article attempts a formal study of technical analysis which is a class of informal prediction rules often preferred to wiener kolmogorov prediction theory by participants of financial markets yet wiener kolmogorov prediction theory provides optimal linear forecasts this article investigates two issues that may explain this contradiction first the article attempts to devise formal algorithms to represent various forms of technical analysis in order to see if these rules are well defined second the article discusses under which conditions if any technical analysis might capture those properties of stock prices left unexploited by linear models of wiener kolmogorov theory copyright 1991 by university of chicago press