wisdom of crowds the value of stock opinions transmitted through social media social media has become a popular venue for individuals to share the results of their own analysis on financial securities this paper investigates the extent to which investor opinions transmitted through social media predict future stock returns and earnings surprises we conduct textual analysis of articles published on one of the most popular social media platforms for investors in the united states we also consider the readers perspective as inferred via commentaries written in response to these articles we find that the views expressed in both articles and commentaries predict future stock returns and earnings surprises

neglected method of separating demand and supply in time series regression this article argues that in many markets quantity is demand determined in the short run but price is supply determined and that the dynamic restrictions between price and quantity implied by the model have been widely neglected in empirical research two examples illustrate our point the demand and supply relationships between inflation and unemployment and between the terms of trade and the trade balance in both specifying quantity as a function of lagged prices in demand and price as a function of lagged quantities in supply rather than concentrating on exogenous shift determinants is sufficient to separate demand and supply

antitrust and technological innovation in the us ideas institutions decisions and impacts 1890 2000 abstract the history of antitrust policy in the us as it relates to technological innovation exhibits major swings every few decades between favoring concentration and favoring deconcentration this paper sketches for each period the contending ideas that frame antitrust technology policy debates the salience of these ideas in the larger antitrust policy process the institutions for agenda setting and decision making in this area the policy decisions themselves and more speculatively the impacts of these decisions on technological innovation and industrial development the paper concludes with a preliminary attempt to identify the cyclical secular and static processes that have shaped the history of this policy area and to use this analysis to inform future policy makers

the refoundation of the symmetric equilibrium in schumpeterian growth models abstract we provide a refoundation of the symmetric growth equilibrium characterizing the research sector of vertical r d driven growth models we argue that the usual assumptions made in this class of models leave the agents indifferent as to where targeting research hence the problem of the allocation of r d investment across sectors is indeterminate by introducing an contamination of confidence in the expected distribution of r d investment we prove that the symmetric structure of r d investment is the unique rational expectations equilibrium compatible with ambiguity averse agents adopting a maxmin strategy

impact of the terms of trade on the u s trade balance a reexamination the right conclusion could be that there is a strong connection between the spectral components with specified periods a possible economic interpretation could identify a strong long term in the sense of the specified periods connection between both series but that would still not allow us to say anything concerning the size and direction of the time delay between the two series for such an analysis we would have to at least consider the phase angles between the components because of the ambivalent meaning of the phase angle in relation to the direction and number of periods the final answer could come only from the time domain analysis however the fact that only spectral components with longer periods i e smaller frequencies show coherency suggests something else in order to influence the balance of trade the changes in the terms of trade should be durable enough mathematical formalization of this concept of durability would therefore be helpful i would propose that further research be done in this respect

uniqueness and indeterminacy on the dynamics of endogenous growth abstract in this paper we study the dynamics of endogenous growth both in the model of lucas and in a generalization that incorporates a labor leisure choice we characterize the regions of the parameter space that give rise to unique equilibria as well as the regions that yield a continuum of equilibria with positive growth rates we find that such multiple equilibria exist for empirically very plausible parameters in particular when the lucas model is modified to incorporate endogenous labor journal of economic literature numbers e00 e3 o40

journalists and the stock market we use exogenous scheduling of wall street journal columnists to identify a causal relation between financial reporting and stock market performance to measure the media s unconditional effect we add columnist fixed effects to a daily regression of excess dow jones industrial average returns relative to standard control variables these fixed effects increase the r super 2 by about 35 indicating each columnist s average persistent bullishness or bearishness to measure the media s conditional effect we interact columnist fixed effects with lagged returns this increases explanatory power by yet another one third and identifies amplification or attenuation of prevailing sentiment as a tool used by financial journalists the author 2012 published by oxford university press on behalf of the society for financial studies all rights reserved for permissions please e mail journals permissions oup com oxford university press

a model of creative destruction with undiversifiable risk and optimising households this paper studies optimal household behaviour in a model of creative destruction the saving technology is characterised by stochastic returns that follow a poisson process it is shown that equilibrium conditions with optimising households differ substantially from equilibrium conditions where investment in r d is determined by firms three out of four market failures disappear and a new market failure resulting from a complementarity in financing r d is identified studying the social optimum shows that it contains as the special case of risk neutrality the social optimum derived in the literature

disagreement and learning dynamic patterns of trade we study volume dynamics when there are disagreements among investors for that purpose we develop a dynamic model in which differences in the interpretation of public information lead to trade we obtain a simple linear equilibrium in closed form in which risk averse agents take into account future trading opportunities when solving for their optimal portfolio allocation using this framework we then study what restrictions on the disagreement process are needed to generate empirically observed patterns in volume and prices we show that having infrequent but major disagreements leads to autocorrelation in volume and correlation between volume and absolute price changes when agents disagree on past news but agree on the interpretation of current news there is learning and the convergence of agents opinions leads to trade

comment on a neglected method of separating demand and supply in time series regression by stephen e haynes and joe a stone this article examines some difficulties associated with the haynes stone model and attempts to clarify how the model can be justified as representing the hypothesis that quantity is demand determined and price is supply determined it also argues that the applications of such a model as was done by haynes and stone might not have resolved the controversies related to the phillips curve and the supply function of exports or imports

the dynamic dependence of fossil energy investor sentiment and renewable energy stock markets abstract this study investigates the dynamic directional information spillover of return and volatility between the fossil energy market investor sentiment towards renewable energy and the renewable energy stock market using the connectedness network approach empirical results show that the spillover effects of the volatility system are generally stronger than that of the return system which suggest that risk transmission among the markets is more obvious in both systems the impact of the fossil energy market especially crude oil on the renewable energy stock market is greater than the impact of investor sentiment on the renewable energy stock market this finding shows that the renewable energy stock market is closely related to the fossil energy market furthermore the rolling window approach is adopted to examine the time varying information spillover among them the dynamic findings suggest that investor sentiment towards renewable energy can explain the return and volatility of renewable energy stock to a certain degree

monopolistic competition business cycles and the composition of aggregate demand abstract we develop a dynamic general equilibrium model with monopolistically competitive firms and endogenous markups and show the possibility of equilibria with persistent fluctuations driven by self fulfilling revisions of expectations for some parameter values such fluctuations are characterized by time series properties similar to those observed in u s postwar business cycles in contrast with the existing literature our results do not rely on the presence of increasing returns or nominal rigidities a key ingredient of the model is the link between markups and the composition of aggregate demand some econometric evidence on the latter is also reported journal of economic literature classification number d43 d58 e32

wavelet based test of co movement and causality between oil and renewable energy stock prices abstract we studied co movement and causality between oil and renewable energy stock prices using continuous and discrete wavelets firstly to obtain information on dynamic correlations over time and for different time scales from wavelet coherence and secondly to obtain information on linear and non linear granger causality in the time frequency domain for general and sectoral renewable energy indices for the period 2006 2015 our findings indicate that dependence between oil and renewable energy returns in the short run was weak but gradually strengthened towards the long run mainly for the period 2008 2012 our causality tests provide evidence against linear causality at higher frequencies and in favour of unidirectional and bidirectional linear causality at lower frequencies in contrast we found consistent evidence of non linear causality running from renewable energy indices to oil prices at different time horizons and mixed evidence of causality running from oil to renewable energy prices these results have potential implications for investors in terms of hedging and for policymakers in terms of policy support decisions regarding the development of renewable energy

self fulfilling prophecies in the quality ladders economy if r d difficulty increases as it accumulates as recent evidence suggests then there is a value in the diversification of the aggregate r d efforts over the whole range of industries in the economy however this paper proves that the quality ladders models allow for self fulfilling prophecies to divert r d from an arbitrary number of sectors with potentially dramatic effects on the dynamics of industry structure and on the long run aggregate growth performance moreover in developing countries perfect markets might allow stagnant monopolies to resist despite the removal of fundamental entry barriers to dynamic competition this kind of coordination failure implies potentially strong effects of socio cultural factors on growth and suggests a positive role for public r d policy even in a framework of semi exogenous growth

the impact of twitter sentiment on renewable energy stocks abstract we study the impact of twitter sentiment and sentiment divergence on returns volatility and trading volumes for renewable energy stocks based on daily time series for twitter sentiment and twitter sentiment divergence we estimate var models and evaluate spillovers between sentiment and renewable energy stock pricing and trading we find that whereas twitter sentiment has no sizeable impact on returns volatility or trading volumes twitter sentiment divergence generates feedback effects on volatility and trading volumes our evidence would indicate that the wisdom of the twitter crowd is not substantial in shaping prices and trading for renewable energy companies

specification of supply behavior in international trade supply behavior in international trade has been notoriously difficult to capture empirically indeed so few published supply studies exist that stern francis and schumacher s 1976 bibliographical survey of price elasticities in international trade devotes over 350 pages to demand estimates but barely 10 pages to supply estimates in recent years only goldstein and khan 1978 and dunlevy 1980 using simultaneous equation estimation techniques have reported estimates of supply behavior in international trade exogenous shocks to demand and supply for traded goods in general influence both quantity and price for supply estimates it is unclear a priori whether the response is more appropriately specified with quantity or price as the dependent variable however if supplying firms in an uncertain world pursue pricing strategies based on past market performance as in zabel 1981 the appropriate specification is a supply price equation in this case prices respond to lagged quantities which implies that the traditional supply quantity specification with present and past prices as explanatory variables cannot capture the dynamic supply behavior in this study we explore the hypothesis that previous attempts to estimate supply behavior have generally failed not only because of the well known problem of simultaneity bias but also because quantity rather than price was specified as the dependent variable section ii presents and discusses traditional supply quantity equations based on quarterly data for aggregate exports and imports for the united kingdom and the united states from 1947 to 1979 section iii briefly discusses the theoretical rationale of a supply price specification and presents estimates of supply price equations based on the same data section iv evaluates the empirical evidence to determine whether a supply quantity or supply price formulation is more appropriate and compares estimates of long run price elasticities of supply based on the two approaches a final section summarizes the conclusions

divergence of sentiment and stock market trading this paper introduces the concept of divergence of sentiment to the behavioral finance literature we measure the distance between people with positive and negative sentiment on a daily basis for 20 countries by using data from status updates on facebook the prediction is that a higher divergence of sentiment leads to more diverging views on prospects and risks and thus to more diverging views on the value of a stock in line with this prediction divergence of sentiment is positively related to trading volume we further predict and find a positive relation between divergence of sentiment and stock price volatility the observed relations are stronger when individual investors are more likely to trade we compare the effect of our country specific measures to a global measure of divergence of sentiment we find that the separate effects of country specific and global divergence measures depend on a country s level of market integration

competitive firm behavior under risk in disequilibrium trading the objective of this paper is to study the behavior of the purely competitive firm in a market in which traders plans may not be realized each period the emphasis of the study is motivated by a desire to introduce explicit price makers into the theory of competitive markets the method of introducing price makers may lead to situations in which markets are not cleared each period and shortages may arise with the realization of plans being in doubt in this environment traders learn to adjust decisions to offset periodic disappointment multiperiod models are introduced to analyze the decision process of the competitive firm in the market and stochastic dynamic programming methods are used to obtain characteristics of optimal plans results are compared to the situation in which plans are always realized

the relative effects of demand and supply on output growth and price change this study demonstrates an analytical model for evaluating the relative importance of demand and supply factors in determining output growth and price change empirical analysis of the 1947 80 data shows that for most industry groups demand effects are more dominant in determining output growth whereas supply effects are more dominant in determining price change the conclusion remains the same when the effects of uncontrollable variables such as taste and technology are excluded the study provides useful information for analyzing the effectiveness of demand and supply management policies in affecting output growth and price change introduction recently the stability and validity of the phillips curve and the effectiveness of demand management policies to deal with stagflation have been questioned by many economists evidence has been accumulated e g eckstein 1984 to suggest that variations in aggregate supply price were the predominant influences on the general price level of the u s economy but little is known about whether demand or supply factors were more dominant in determining economic growth studies on the relative importance of demand and supply factors at the industry level have been very few but the recent studies by houthakker 1979 and 1981 suggested the importance of supply shifts and or economies of

endogenous growth without scale effects comment segerstrom 1998 demonstrates that the social optimum requires radical technological breakthroughs to be treated less favorably than incremental innovations in a growing economy the aim of this note is to assess the robustness of this welfare result on the basis of two levels of generalization i the elasticity of substitution between any two goods is allowed to be larger than one and ii inter industry spillovers are introduced we show that segerstrom s results can be reversed it is also shown that in contrast to segerstrom r d subsidies can be globally optimal irrespective of the size of innovation when inter industry spillovers are large

volume volatility and public news announcements we provide new empirical evidence for the way in which financial markets process information our results rely critically on high frequency intraday price and volume data for the s p 500 equity portfolio and u s treasury bonds along with new econometric techniques for making inference on the relationship between trading intensity and spot volatility around public news announcements consistent with the predictions derived from a theoretical model in which investors agree to disagree our estimates for the intraday volume volatility elasticity around important news announcements are systematically below unity our elasticity estimates also decrease significantly with measures of disagreements in beliefs economic uncertainty and textual based sentiment further highlighting the key role played by differences of opinion

animal spirits and the composition of innovation this paper shows that the schumpeterian model with both vertical and horizontal innovative research admits many more equilibria than the unique symmetric balanced growth path bgp usually highlighted in the literature each of a continuum of bgps is characterized by a different composition of aggregate r d vertical versus horizontal this appears if firms expect self fulfilling waves of enthusiasm in the newly introduced sectors as is very common in the real world pioneers are challenged by more outsiders and the first monopoly of every new good is likely to last less than in more mature industries by expecting this horizontal innovation is depressed while vertical innovation is more intense such waves of enthusiasm have a positive effect on growth rates and a negative effect on consumption levels

is there dependence and systemic risk between oil and renewable energy stock prices abstract we study systemic risk and dependence between oil and renewable energy markets using copulas to characterize the dependence structure and to compute the conditional value at risk as a measure of systemic risk we found significant time varying average and symmetric tail dependence between oil returns and several global and sectoral renewable energy indices our evidence on systemic risk indicates that oil price dynamics significantly contributes around 30 to downside and upside risk of renewable energy companies these results have important implications for risk management and renewable energy policies

government spending composition technical change and wage inequality in this paper we argue that government spending played a significant role in stimulating the wave of innovation that hit the u s economy in the late 1970s and in the 1980s as well as the simultaneous increase in inequality and in education attainments since the late 1970s u s policymakers began targeting commercial innovations more directly and explicitly we focus on the shift in the composition of public demand toward high tech goods which by increasing the market size of innovative firms functions as a de facto innovation policy tool we build a quality ladders non scale growth model with heterogeneous industries and endogenous supply of skills and show that an increase in the technological content of public spending stimulates r d raises the wage of skilled workers and at the same time stimulates human capital accumulation a calibrated version of the model suggests that government policy explains between 12 and 15 of the observed increase in wage inequality in the period 1976 1991 jel e62 j31 o33 o41