market frictions a unified model of search costs and switching costs it is well known that search costs and switching costs can create market power by constraining the ability of consumers to change suppliers while previous research has examined each cost in isolation this paper demonstrates the benefits of examining the two types of friction in unison the paper shows how subtle distinctions between the two costs can provide important differences in their effects upon consumer behaviour competition and welfare in addition the paper also illustrates a simple empirical methodology for estimating separate measures of both costs while demonstrating a potential bias that can arise if only one cost is considered

the real effects of liquidity during the financial crisis evidence from automobiles illiquidity in short term credit markets during the financial crisis might have severely curtailed the supply of nonbank consumer credit using a new data set linking every car sold in the united states to the credit supplier involved in each transaction we find that the collapse of the asset backed commercial paper market reduced the financing capacity of such nonbank lenders as captive leasing companies in the automobile industry as a result car sales in counties that traditionally depended on nonbank lenders declined sharply although other lenders increased their supply of credit the net aggregate effect of illiquidity on car sales is large and negative we conclude that the decline in auto sales during the financial crisis was caused in part by a credit supply shock driven by the illiquidity of the most important providers of consumer finance in the auto loan market these results also imply that interventions aimed at arresting illiquidity in short term credit markets might have helped contain the real effects of the crisis

day of the week effects and asset returns the number of empirical studies using daily stock returns is rapidly increasing researchers generally assume that the distribution of stock returns is identical for all days of the week a convenient statistical assumption but not a necessary condition of market equilibrium nevertheless there are reasons to suspect that the distribution of returns may vary according to the day of the week the most obvious is the impact of weekends on monday s return since monday s return is calculated over three instead of one calender day the mean and variance may well be higher on monday compared with any other daily return perhaps three times as large previous research has examined the daily distribution of stock returns for a monday effect while fama 1965 does not compare daily mean returns he does report that monday s variance is about 20o greater than other daily returns with a traditional distributional assumption regarding the returns on a financial asset specifies that the expected returns are identical for all days of the week contrary to this plausible assumption this paper discovers that the expected returns on common stocks and treasury bills are not constant across days of the week the most notable evidence is for monday s returns where the mean is unusually low or even negative several explanations of the results are investigated but none proves satisfactory aside from documenting significant day of the week effects the implications of the results for tests of market efficiency are examined while market adjusted returns continue to exhibit day of the week effects these effects are no longer concentrated on monday during the last year we have had many conversations with our colleagues throughout the professions we are particularly thankful to the participants at sessions of the western and american finance associations where preliminary versions of this paper were presented special thanks are due to gene fama gailen hite jon ingersoll robert jarrow merton miller clifford smith and rex thompson the expert research assistance of frank rabinovitch and youngsup yun is gratefully acknowledged 1 the list of papers using daily stock returns is too long to name recent examples include charest 1978 dodd 1980 banz 1981 and reinganum 1981

world stock markets some random walk tests 1982 world stock markets some random walk tests applied economics vol 14 no 5 pp 515 531

innovation complementarity and environmental productivity effects reality or delusion evidence from the eu abstract innovation is a key element behind the achievement of desired environmental and economic performances regarding co2 mitigation strategies would require cuts in emissions of around 80 90 with respect to 1990 by 2050 in the eu we investigate whether complementarity namely integration between the adoption of environmental innovation measures and other technological and organizational innovations is a factor that has supported reduction in co2 emissions per value added that is environmental productivity we merge new eu innovation and wiod data to assess the innovation effects on sector co2 performances at a wide eu level we find that jointly adopting different innovations is not a widespread factor behind increases in environmental productivity nevertheless even though complementarity is not a low hanging fruit a case where innovation complementarity arises is for manufacturing sectors that integrate eco innovations with product innovations one example of this integrated action is a strategy that pursues energy efficiency with product value enhancement we believe that the lack of integrated innovation adoption behind environmental productivity performance is a signal of the current weaknesses economies face in tackling climate change and green economy challenges incremental rather than more radical strategies have predominated so far the latter have been confined to industrial niches in terms of the number of involved firms this is probably insufficient when we look at long term economic and environmental goals

a weak form evaluation of the efficiency of the rotterdam and italian oil spot markets abstract we examine whether the efficient market hypothesis can be applied to the rotterdam and italian oil markets by analysing the log price changes observed in those markets for monthly data during the period january 1980 to december 1987 the objective is to investigate the leptokurticity in observed distributions of low price changes the stable paretian distributions have been used to test the leptokurtic distributions

continuity and reversal in oil spot price movements abstract the hypothesis that prices follow a random walk is tested using daily data for 1978 1984 on the rotterdam spot gas oil market the method uses a filter test statistic to evaluate possible dependencies between successive price changes in the movement domain the results show a significant tendency for small price changes to persist but for reversal to be exhibited for larger price changes it is shown that this dependency can be exploited in a very profitable trading rule the hypothesis that the gas oil market is efficient is rejected this is attributed to the relative immaturity of oil spot markets

a note on quarterly returns to investment in ordinary shares 1919 1970 two tests of market efficiency this note analyses the data of foldes and watson 1982a it gives some statistics to test for weak form efficiency fama 1976 for quarterly returns xt for a valueand equally weighted equity portfolio and for 2 per cent consols gross and net of tax all series show a very high degree of randomness which implies a high quality in index construction the second test has returns for shares and consols regressed on inflation for the whole period and for five sub periods to see if they account for inflation foldes and watson 1982b in an excellent and detailed paper have examined uk and us equity portfolio returns over 1926 1970 for normality stationarity seasonal variation autocorrelation and a variance curve the autocorrelation section uses spectral analysis integrated spectra and a firstorder autoregression for the united states to see if the series are random it used only one uk equity portfolio value weighted money terms gross of tax but the spectra of this and value weights real terms and equal weights money terms were similar spectral analysis is the least reliable method of testing for dependence in financial returns given the very small samples used here and the need for covariance stationarity for return data this is discussed in praetz 1979 with the very difficult problem of testing for a flat spectrum the time domain tests using serial correlations and a runs test are much more powerful and easier to understand table 1 comprises 12 quarterly serial correlation coefficients r l r 12 an omnibus test of them chi squared 24 124 r j 2 durbin watson dw statistic dw xt xt 1 2 x2 and z runs a standardized statistic of the number of runs minus its expectation over the standard deviation of runs it has value weighted and equally weighted equity portfolios and 24 per cent consols gross and net of tax for whole period a 1 per cent significance level is used because of the large sample however not one statistic is significant supporting a very high degree of randomness a quarterly seasonal pattern praetz 1975 would have large positive values at r 4 r 8 etc which is clearly not the case here weak form efficiency means that a market cannot be exploited systematically for economic profit which is supported by the very low values of the statistics in table 1 cooper 1982 has studied the uk and other countries for randomness but at daily weekly and monthly intervals so the quarterly data used here are for a much longer period of time the only other index with dividends added over a comparable period is the de zoete equity index which has much more dependence in its returns over time benjamin 1980 the stock returns and inflation are related to market efficiency in an efficient market all relevant public information such as inflation should be reflected in market prices this is the semi strong form of market efficiency

market information and price volatility in petroleum derivatives spot and futures markets some new york evidence abstract this paper examines the relationship between petroleum futures trading market information and spot prices it tests the hypothesis that there is increased spot market information with futures trading of various petroleum derivatives for weekly data during the period january 1970 to july 1985 at the new york mercantile exchange increased market information with futures trading is indicated by the insignificance of coefficients of past prices in spot price regressions in periods with futures trading however the estimates of the coefficient of variation indicate that price volatility tends to increase with futures trading thus traders seem better informed with futures trading although the advantages of increased market information might potentially be undermined by increased price volatility as in the case of regular gasoline

the semi strong form efficiency of the london metal exchange 1983 the semi strong form efficiency of the london metal exchange applied economics vol 15 no 5 pp 681 698

toward efficiency in the crude oil market the official opec prices of crude oil before the collapse in the oil market in the mid 1980s can be interpreted as contract prices and analysed on the basis of the theory of futures or forward markets this paper uses the generalized method of moments estimation technique to test for efficiency in the relationship between the official prices and the ex post spot prices at the time of delivery efficiency is rejected for the sample period 1978 1985 as a whole but evidence is found of improvements over time further the gmm wald and hansen tests although asymptotically equivalent are shown to differ greatly when applied to a small sample of monthly oil price data

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

comparative statics of the firm abstract complementarities arise naturally in diverse models of optimal decision making in a firm theoretical properties of supermodular functions provide a powerful tool for analyzing qualitative properties in such circumstances this paper considers a general model of the firm and gives sufficient conditions for complementarities to hold and for optimal decisions to be monotone with a parameter a variety of specific models of the firm are shown to satisfy these conditions necessary conditions delimit those models of the firm that may exhibit monotone optimal decisions journal of economic literature classification numbers b41 c61 d20 l00

equilibrium with product differentiation tive consumer formulations is used to examine the properties of single and multiple price equilibria conditions under which decreases in the intensity of consumer preferences reduce price are given it is shown that with certain types of demand curves entry can eliminate price cost markups even given product differentiation if competition is localized it is demonstrated that entry does not affect the markup finally the effect of spurious product differentiation on price is examined

number of sellers average prices and price dispersion abstract a variety of models provide differing predictions regarding the effect of an increase in the number of competitors in a market seller density on prices and price dispersion we review different approaches to generating equilibrium price dispersion and then empirically estimate the relationship between seller density average product price and price dispersion in the retail gasoline industry using four unique gasoline price data sets controlling for station level characteristics we find that an increase in station density consistently decreases both price levels and price dispersion across four geographical areas

does corporate lending by banks and finance companies differ evidence on specialization in private debt contracting this paper establishes empirically the existence of specialization in private market corporate lending adding a new dimension to the public versus private debt distinctions now common in the literature comparing corporate loans made by banks and by finance companies we find that the two types of intermediaries are equally likely to finance information problematic firms however finance companies tend to serve observably riskier borrowers particularly more leveraged borrowers evidence supports both regulatory and reputation based explanations for this specialization in passing we shed light on various theories of debt contracting and intermediation and present facts about finance companies

emergence of captive finance companies and risk segmentation in loan markets theory and evidence this paper presents a theoretical model and empirical evidence of risk segmentation of the secured consumer installment loan market by two different types of lending institutions independent lending institutions and captive finance companies a consumer installment loan is a credit arrangement repaid through periodic installment payments over a specific length of time in general consumer installment loans are used for financing the purchase of expensive durable

relationship between spatial agglomeration and hotel prices evidence from business and tourism consumers abstract in this paper we examine the relationship between number of local competitors and both the average and the dispersion of retail prices in urban hotels using a dataset from the metropolitan area of madrid spain by controlling for hotel characteristics and spatial factors we obtained results for each of the days in one week in line with predictions derived from the traditional monopolistic approach empirical results consistently indicate that a greater density of competitors implies a lower average and less dispersion of local prices moreover we found evidence which supports the idea that the effect of local agglomeration on average prices is particularly weaker at weekends this in turn indirectly suggests that within the metropolitan area there is a greater degree of substitution in hotel locations for tourism consumers than for business consumers

efficient market hypothesis evidence from a small open economy this article studies the efficient market hypothesis for the istanbul stock exchange national 100 isen 100 price index within the lumsdaine and papell two structural breaks unit root test framework the main finding of the article shows that the isen 100 index is characterized by a unit root with two structural breaks which is consistent with the efficient market hypothesis in addition the article applies the augmented dickey fuller test runs test and the variance ratio test to test the weak form efficiency of the isen 100 the analyses are repeated for three sub periods delineated in view of the endogenously determined break points

monopolistic competition and preference diversity approach our model is especially attractive because it starts from economic primitives a specification of the set of possible individual preference patterns it shows how specific properties of the distribution of preferences translate into properties of aggregate demand this allows us to understand the relationship between the distribution of preferences and the degree to which the market introduces biases in product selection this paper presents a general model of the demand for differentiated products which has as special cases two of the most popular approaches used to analyse welfare and competition in monopolistically competitive markets the model of spatial competition on the circle and the model of symmetric aggregate demand the circle model is attractive because both demand and costs have a definite and easy to visualize physical foundation and because it is tractable salop 1979 provides an exemplary modem analysis with this model one can analyze the relationship between the optimal amount of product variety and the amount which a monopolistically competitive market will support in many plausible cases competition produces too much variety such a strong conclusion raises questions of robustness almost simultaneously spence 1976 and dixit and stiglitz 1977 developed an alternative approach to monopolistic competition based upon the chamberlinian assumption of symmetry see also shubik 1959 rather than specifying a distribution of preferences and deriving demand through aggregation as did salop and his predecessors these authors started by specifying a symmetric aggregate benefit function indicating how social welfare depends on the amounts of the various products supplied both spence and dixit stiglitz were able to show that the welfare conclusions from the circle model were not robust depending on the functional form of the benefit function equilibrium may entail either excessive or insufficient product variety 1 the assumption of symmetric demand has proven fruitful in the analysis of many economic problems it is therefore natural to ask what distribution of tastes would give

an empirical analysis of personal bankruptcy and delinquency this article uses a new dataset of credit card accounts to analyze credit card delinquency personal bankruptcy and the stability of credit risk models we estimate duration models for default and assess the relative importance of different variables in predicting default we investigate how the propensity to default has changed over time disentangling the two leading explanations for the recent increase in default rates a deterioration in the risk composition of borrowers versus an increase in borrowers willingness to default due to declines in default costs even after controlling for risk composition and economic fundamentals the propensity to default significantly increased between 1995 and 1997 standard default models missed an important time varying default factor consistent with a decline in default costs debt issued by consumers is an understudied asset class there has been particularly little academic study of recent trends in default on this debt between 1994 and 1997 the number of personal bankruptcy filings in the united states rose by about 75 the 1 35 million filings in 1997 represented well over 1 of u s households delinquency rates on credit cards rose almost as sharply federal reserve bank of cleveland 1998 the resulting losses to lenders amounted to a sizable fraction of the interest payments they collect potentially raising the average cost of credit these trends in default both in bankruptcy and delinquency are especially surprising in light of the strong economy over the period they provide an unusually rich source of variation to test the stability of models that forecast personal default and of credit risk models more generally there are two leading explanations for these trends first the risk composition of borrowers might have worsened under the risk effect less

heterogeneous beliefs regret and uncertainty the role of speculation in energy price dynamics abstract this paper proposes to investigate the impact of financialization on energy markets oil gas coal and electricity european forward prices during both normal times and periods of extreme fluctuation by using an original behavioral and emotional approach with this aim we propose a new theoretical and empirical framework based on a heterogeneous agents model in which fundamentalists and chartists co exist and are subject to regret and uncertainty we find significant evidence that energy markets are composed of heterogeneous traders who behave differently depending on the intensity of the price fluctuations and the uncertainty context in particular energy prices are governed primarily by fundamental and chartist agents that are neutral to uncertainty during normal times whereas these prices face irrational chartist investors averse to uncertainty during periods of extreme fluctuations in this context the recent surge in energy prices can be viewed as the consequence of irrational exuberance our new theoretical model is suitable for modeling energy price dynamics and outperforms both the random walk and the arma model in out of sample predictive ability

the behaviour of hong kong stock prices the primary function of a stock market is to allocate resources to the most profitable investment opportunities if stock prices provide accurate signals for resource allocation firms are able to make correct production investment decisions and investors are able to choose the most suitable stocks for investment these choices are only possible if the market is efficient that is if stock prices fully reflect all available information hong kong is now an international financial centre although hong kong s stock market is ranked as one of the five largest in the world in terms of turnover little research has been devoted to the behaviour of its stock prices this is a study of the efficiency of hong kong s stock market it is based upon two widely accepted statistical tests namely serial correlation analysis and runs tests data used cover the daily prices of 28 major hong kong stocks over a period of four years from 1977 to 1980 the evidence is mixed it does not provide clear support for the e

volatility in an era of reduced uncertainty lessons from pax britannica abstract although it has been well established that financial volatility is related to news and macroeconomic shocks less emphasis has been placed on the importance of underlying economic and political stability in this paper we study the behavior of consol returns since 1729 and identify a greater than 50 decline in volatility from the end of the napoleonic wars in 1815 until the first world war news events and macroeconomic variables cannot account for this extended period of reduced volatility underlying political stability under pax britannica seems to be a more likely explanation

the economics of product variety a survey demand for variety may arise from a taste for diversity in individual consumption and or from diversity in tastes even when each consumer chooses a single variant the full degree of variety potentially demanded will not in general be supplied because scale economies even to a small degree mean that the potential welfare or revenue gain from greater variety must be balanced against the lower unit production costs with fewer variants the economics of product variety consists essentially in analysing the effect of this balance in different situations and comparing the degree of product variety for different market structures with each other and with the optimum the survey commences with the work on market structures with single product firms generalized monopolistic competition tracing modern developments in both the chamberlinian and hotelling traditions the latter has been particularly fruitful due to the expansion of the original locational ideas into virtual spaces in product characteristics the emphasis in recent work on product variety has been on multiproduct firms in both monopolistic and oligopolistic structures including strategic market preemption although most work has been in a full information context there have been advances in product variety under imperfect information either by consumers to properties of the firms products or firms as to consumers demands

differential importance and comparative statics an application to inventory management abstract in this work we deal with the problem of establishing which parameters impact an inventory policy the most a new sensitivity measure is introduced by relating the differential importance d and the comparative statics cs techniques we discuss the properties of the new indicator and show that it shares the additivity property we provide the expression of for optimization models numerical results are offered for the sensitivity analysis of a recently introduced inventory management model

collateral and rationing sorting equilibria in monopolistic and competitive credit markets the authors examine how market structure affects credit allocation under universal risk neutrality and asymmetric information about borrowers they consider both monopolistic and perf ectly competitive banks and examine the role of collateral in each ca se when a bank is a monopolist on the loan side they find collatera l is never used and asymmetric information results in reduced bank le nding under perfect competition collateral has a useful sorting rol e moreover rationing is possible even with collateral availability and perfectly elastic deposit supply in this setting the authors sh ow co signers are valuable social welfare properties of the monopoly and competitive equilibria are also compared copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

value of an additional firm in monopolistic competition the paper develops a model of monopolistic competition in which the satisfaction levels consumers get from products are independently and identically distributed potential substitution among products then generates demand curves through the mechanism of order statistics the value of extra variety can be calculated directly pareto lognormal and beta distributions are investigated using numerical integration some but not all cases support the argument that the optimal number of firms exceeds the equilibrium number

infectious disease productivity and scale in open and closed animal production systems trade in feeder animals creates externalities when animal diseases can spread beyond the purchasing farm if growers choose between open and closed production systems then nash equilibrium likely involves excessive trading while first best equilibrium involves market wide adoption of either an open trade or closed farm system equilibrium may entail heterogeneous systems if so then the feeder trade should be restricted supply response to an increase in marginal costs may be positive within a farm infectious disease risk can create decreasing returns to scale when the technology is otherwise increasing returns contractual procurement and damage control technologies will likely increase scale in finishing

efficiency of the turkish stock exchange with respect to monetary variables a cointegration analysis in this study we test the semistrong form of the efficient market hypothesis in turkey by using the recently developed techniques in time series econometrics namely unit roots and cointegration the long run relationship between stock prices and inflation is investigated by assuming the possible existence of a proxy effect conclusions are made as to the efficiency of the turkish stock exchange and its possible implications for investors to our knowledge this is among the pioneering studies conducted in an emerging market that uses an updated econometric methodology to allow for an analysis of long run steady state properties together with short run dynamics

choice interactions and business strategy choice settings are strategic to the extent that they entail cross sectional or intertemporal linkages these same factors may impose daunting demands on decision makers we develop a graph theoretic generalization of the nk model of fitness landscapes to model the way in which policy choices may be more or less strategic we use this structure to examine through simulation how fully articulated a strategy or set of policy choices must be to achieve a high level of performance and how feasible it is to offset past strategic mistakes through tactical adjustments instead of alignment our analysis highlights the role of asymmetry in the interaction of strategic choices and in particular the degree to which choices vary in terms of being influential dependent or autonomous from other choices

supermodularity and complementarity in economics an elementary survey the literature on supermodular optimization and games is surveyed from the perspective of potential users in economics this methodology provides a new approach for comparative statics based only on critical assumptions and allows a general analysis of games with strategic complementarities the results are presented in a simplified yet rigourous manner without reference to lattice theory for the special case of one dimensional parameter and actions sets with the emphasis being on wide accessibility detailed applications are presented for well known models of consumer behavior monopoly pass through bertrand and cournot competition strategic r d search and matching wherever appropriate useful tricks for applications and comparative comments are inserted

commodity futures and market efficiency we propose a comprehensive treatment of the leverage effect i e the relationship between returns and volatility of a specific asset focusing on energy commodities futures namely brent and wti crude oils natural gas and heating oil after estimating the volatility process without assuming any specific form of its behavior we find the volatility to be long term dependent with the hurst exponent on a verge of stationarity and non stationarity to overcome such complication we utilize the detrended cross correlation and the detrending moving average cross correlation coefficients and we find the standard leverage effect for both crude oils and heating oil for natural gas we find the inverse leverage effect additionally we report that the strength of the leverage effects is scale dependent finally we also show that none of the effects between returns and volatility is detected as the long term cross correlated one these findings can be further utilized to enhance forecasting models and mainly in the risk management and portfolio diversification

is the spot market for oil products efficient some rotterdam evidence abstract this paper presents evidence relating to the efficiency of the rotterdam market for oil products analysis of daily weekly and monthly price changes for gas oil during the period 1978 1983 results in the rejection of the efficiency hypothesis ie relative price changes have been serially dependent on the basis of this observation a very simple trading rule is developed this rule is tested out simulating market transactions during the first two quarters of 1984 the financial outcome of this game turns out to be rather rewarding

demand for differentiated products discrete choice models and the characteristics approach we propose a specific characteristics framework in order to construct linkages between alternative conceptual approaches to modelling product differentiation first it is shown that a demand system which satisfies the gross substitutes property imposes specific requirements on the locations of products in particular the dimension of the characteristics space must be larger than or equal to the number of products minus one we then identify a method for casting a given demand system subject to certain restrictions into our characteristics framework this is illustrated for the logit probit and linear probability models of discrete choice theory finally we find a characteristics representation of the ces representative consumer

predation and cross subsidization in the value maximizing multiproduct firm predation occurs when a firm engages in the temporary strategy of setting prices below production costs to damage or destroy existing competitors one form of predation occurs when a multiproduct or conglomerate firm obtains revenues in excess of production costs on goods sold in monopolized markets and uses these rents to subsidize the production of goods sold in competitive markets indeed the fact that cross subsidization is precluded in long run competitive equilibrium and is thus synonymous with predation has frequently been demonstrated in the literature previous analyses of the relationship between cross subsidization as defined by the difference in the additional or incremental costs and revenues of producing a specific group of commodities and predation have been conducted under the behavioral postulate of profit maximization the purpose of this paper is to reexamine this relationship given the alternative assumption of value maximization the assumption of value maximization leads to different results 2 specifically it is shown that for a multiproduct firm producing goods with different risk characteristics e g cyclical and counter cyclical stochastic demand cross subsidization can be both a value maximizing strategy and a characteristic of long run competitive equilibrium thus a multiproduct firm may give the appearance of engaging in cross subsidization for the purpose of predatory pricing without ever having considered the effects of its decisions on actual or potential competition the remainder of this paper is organized as follows section ii presents the assumptions and model of the analysis the main features of this model are the assumption of

weak form efficiency in the nineteenth century a study of daily prices in the london market for 3 per cent consols 1821 1860 tests for weak form efficiency provide one benchmark against which the informational efficiency of a market may be judged this article reports the results of weak form efficiency tests of the london market for 3 percent consols for the period 1821 60 using approximately 10 000 daily price changes the results are similar to those found in contemporary markets suggesting that this market was efficient in the sense defined copyright 1989 by the london school of economics and political science

is environmental innovation embedded within high performance organisational changes the role of human resource management and complementarity in green business strategies abstract this paper investigates whether firms joint implementation of organisational innovation and training may foster their adoption of environmental innovation ei and if this correlation falls within porter hypothesis ph framework we study the relationship of complementarity between strategies of high performance work practices hpwp and human resource management hrm when ei adoption is the firms objective using an original dataset on 555 italian industrial firms regarding ei hpwp and hrm coherent with the last cis2006 2008 survey results show that sector specificity matter the only case in which strict complementarity is observed in organisational change concerns co 2 abatement a relatively complex type of ei but this is true only when the sample is restricted to more polluting and regulated sectors this evidence is coherent with the porter hypothesis complementarity related adoption of ei is an element of organisational change in firms that are subject to more stringent environmental regulations nevertheless the fact that strict complementarity is not a diffuse factor behind the adoption of all environmental innovation indeed does not come as a surprise at this stage in the development of green strategies the share of eco firms is still limited even in advanced countries that are seeking tools for a new competitiveness the full integration of eis within the internal capabilities and firm s own assets is far from being reached even in advanced and competitive industrial settings

random walk tests for the lisbon stock market this article reports the results of tests on the weak form market efficiency applied to the psi 20 index prices of the lisbon stock market from january 1993 to december 2006 as an emerging stock market it is unlikely that it is fully information efficient but we show that the level of weak form efficiency has increased in recent years we use a serial correlation test a runs test an augmented dickey fuller adf test and the multiple variance ratio test proposed by lo and mackinlay 1988 for the hypothesis that the stock market index follows a random walk nontrading or infrequent trading is not an issue because the psi 20 includes only the 20 most traded shares the tests are performed using daily weekly and monthly returns for the whole period and for five sub periods which reflect different trends in the market we find mixed evidence but on the whole our results show that the portuguese stock market index has been approaching a random walk behaviour since 2000 with a decrease in the serial d

information costs and the organization of credit markets a theory of indirect lending this paper explains indirect lending as a strategy for reducing a bank s cost of screening borrowers commercial banks appear to ration credit by rejecting some direct loan applicants although they accept higher risk borrowers who apply for loans indirectly through retailers however the more thorough credit check on direct loans causes applicants to sort themselves according to risk indirect applicants signal their higher risk through their choice of financing since banks gather more accurate information on direct applicants the two types of contracts should differ in predictable ways these implications are tested with federal reserve data on 5 000 automobile loans