growth and unemployment this paper analyses the effects of growth on long run unemployment using a search model of equilibrium unemployment where growth arises explicitly from the introduction of new technologies that require labour reallocation for their implementation the analysis uncovers and compares between two competing effects of growth on unemployment the first is a capitalisation effect whereby an increase in growth raises the capitalised returns from creating jobs and consequently reduces the equilibrium rate of unemployment the second is a creative destruction effect whereby an increase in growth reduces the duration of a job match thereby raising the equilibrium level of unemployment both directly by raising the job separation rate and indirectly by discouraging the creation of job vacancies this paper asks the question of how the rate of economic growth affects unemployment in the long run the main consideration that leads us to think that this is an interesting question has to do with the re allocative aspect of growth in the long run faster economic growth must come from a faster increase in knowledge to the extent that the advancement of knowledge is embodied in industrial innovations it is likely to raise the job destruction rate through automation skill obsolescence and the bankruptcy associated with the process of creative destruction in short increased growth is likely to produce an increased rate of job turnover and the search theories of lucas and prescott 1974 and pissarides 1990 imply that an increased rate of job turnover will result in a higher natural rate of unemployment this conclusion is also consistent with the empirical results of davis and haltiwanger 1990 which show that periods of high unemployment tend to be periods of high job turnover at the establishment level it suggests the possibility of a positive longrun tradeoff between growth and unemployment at least over some range there has been relatively little attention paid to our question in the literature on longrun determinants of unemployment for example the recent empirical examination by layard nickell and jackman 1991 of unemployment rates among oecd countries did not even consider the rate of economic growth as a possible explanatory variable this is consistent with the seminal theoretical work of phelps 1968 which implies that the natural rate of unemployment is independent of the rate of productivity growth the only

competitive cross subsidization this paper analyzes competitive pricing policies by multiproduct firms facing heterogeneous buying patterns we show that cross subsidization arises when firms have comparative advantages on different products but are equally efficient overall firms earn a profit from multi stop shoppers by charging positive margins on their strong products but as price competition for one stop shoppers drives total margins down to zero they price weaker products below cost banning below cost pricing leads to higher profits and higher prices for one stop shoppers and may reduce consumer surplus as well as total social welfare

the growth potential of startups over the business cycle this paper shows that employment in cohorts of us firms is strongly influenced by aggregate conditions at the time of their entry employment fluctuations of startups are procyclical they persist into later years and cohort level employment variations are largely driven by differences in firm size rather than the number of firms an estimated general equilibrium firm dynamics model reveals that aggregate conditions at birth rather than post entry choices drive the majority of cohort level employment variation by affecting the share of startups with high growth potential in the aggregate changes in startup conditions result in large slow moving fluctuations in employment

demand information and competition why do food prices fall at seasonal demand peaks prices for seasonal food products fall at demand peaks price declines are not driven by falling agricultural input prices indeed farm to retail margins narrow sharply i use electronic scanner data from a sample of us supermarkets to show that seasonal price declines are closely linked to market concentration and are much larger in markets with several rivals than where a single brand dominates seasonal demand increases reduce the effective costs of informative advertising and increased informative advertising by retailers and manufacturers in turn may allow for increased market information and greater price sensitivity on the part of buyers

the role of firm size in bilateral bargaining a study of the cable television industry we examine the effect of buyer merger on bilateral negotiations between a supplier and n buyers merger may have bargaining effects in addition to the usual efficiency effects the effect of merger on the buyers bargaining position depends on the curvature of the supplier s gross surplus function merger enhances worsens the buyers bargaining position if the function is concave convex based on a panel of advertising revenue in the cable television industry our estimates indicate that the gross surplus function for suppliers of program services is convex this result suggests that cable operators integrate horizontally to realize efficiency gains rather than to enhance their bargaining position vis a vis program suppliers

the brevity and violence of contractions and expansions abstract early studies of business cycles argued that contractions in economic activity were briefer shorter and more violent rapid than expansions this paper systematically investigates this claim and in the process discovers a robust new business cycle fact contractions in employment are briefer and more violent than expansions but we cannot reject the null of equal brevity and violence for expansions and contractions in output the difference arises because employment typically lags output around peaks but they coincide in their troughs we discuss the performance of existing business cycle models in accounting for this fact and conclude that none can fully account for it we then show that a business cycle model with asymmetric adjustment costs on employment and a choice of when to scrap old technologies can account for the business cycle fact both qualitatively and quantitatively

creative destruction and uncertainty uncertainty rises in recessions but does uncertainty cause downturns or vice versa this paper argues that counter cyclical uncertainty fluctuations are a by product of technology growth in a firm dynamics model with endogenous technology adoption faster technology growth widens the dispersion of firm level productivity shocks a benchmark uncertainty measure moreover faster technology growth spurs a creative destruction process generates a temporary downturn and renders uncertainty counter cyclical estimates from structural vector autoregressions vars on u s data confirm the model s predictions on average 1 4 of the cyclical variation in uncertainty is driven by technology shocks this fraction rises to 2 3 around the dot com bubble

productivity and unemployment over the business cycle abstract the low correlation between cyclical unemployment and productivity over the post war period hides a large sign switch in the mid 1980s from significantly negative the correlation became significantly positive using a search model of unemployment with nominal rigidities and variable labor effort i show that technology shocks can generate a positive unemployment productivity correlation whereas non technology shocks i e aggregate demand shocks tend to do the opposite in this context i identify two events that can quantitatively explain the increase in the correlation i a sharp drop in the volatility of non technology shocks in the mid 1980s and ii a decline in the response of productivity to non technology shocks which from procyclical became acyclical in the last 25 years

the timing and magnitude of retail store markdowns evidence from weekends and holidays we examine daily prices of eight goods at seventeen retail stores collected in ann arbor michigan over a four month period from november 1 to february 28 we focus on weekly and seasonal price patterns and on the frequency of price markdowns or sales there were frequent markdowns in the intensive shopping period prior to christmas and a tendency for such sales to occur on weekends we interpret these findings as evidence that a significant number of markdowns are timed to occur when shopping intensity is exogenously high we complement the imperfect information based motives for sales in the literature by contributing an additional element based on the role of bulk shopping and increasing returns in the shopping technology

insurer hospital bargaining negotiated discounts in post deregulation connecticut this paper uses unique data from the state of connecticut to examine discounting patterns in the state s hospital industry for the years following deregulation 1995 1998 the data provide a rare opportunity to study payer level differences in negotiated discounts for hospital services in addition to presenting descriptive evidence on how discounts vary across payers payer types and hospital types this study uses matched revenue data to analyze the economic determinants of discount magnitudes payer size appears to affect bargaining power but the economic significance of the effect is small the data exhibit patterns consistent with a bargaining explanation in which discount magnitudes depend critically on payers abilities to channel patients to hospitals with which favorable discounts have been negotiated

inelastic buyers and competition we precisely measure how competition limits the capacity of sellers to appropriate surplus from less elastic consumers the evidence originates from pricing strategies of italian pharmacists in response to exogenous inflows of parents of newborn babies among their buyers population based laws allow us to use a rdd to compare different competitive environments while more newborn babies have no effect on the price of hygiene products under intense competition we observe a price increase when competition is low this effect is not driven by increasing costs because for diapers demanded by newborns only we see no effect independently of competition this article is protected by copyright all rights reserved

the cyclicality of labor market flows a multiple shock approach abstract in this paper we aim to establish some stylized facts about the relative contributions of the job finding and separation rates to unemployment dynamics depending on the nature of structural shocks the shocks in our bayesian structural var model are identified using a sign restriction approach and capture shifts in the three conditions determining labor market equilibrium in matching models the beveridge curve and the job creation and job destruction conditions using both us and french data we identify an aggregate shock to match profitability the aggregate profitability shock a shock specific to existing jobs the reallocation shock and a shock to the efficiency of the matching process the matching efficiency shock we find that the relative contributions of the job finding and separation rates are notably different across shocks in both countries but are similar across countries for each type of shock labor market dynamics appear to be transatlantic despite well known institutional differences however it must be emphasized that the reaction of the labor market variables to the matching efficiency shock seems more muted in the us than in france

the dynamic eects of monetary policy a structural factor model approach we use the structural factor model proposed by forni giannone lippi and reichlin 2007 to study the eects of monetary policy the advantage with respect to the traditional vector autoregression model is that we can exploit information from a large data set made up of 112 us monthly macroeconomic series monetary policy shocks are identified using a standard recursive scheme in which the impact eects

sales and firm entry the case of wal mart temporary price reductions or sales have become increasingly important in the evolution of the price level we present a model of repeated price competition to illustrate how entry causes incumbents to alternate between high and low prices using a six year panel of weekly observations from a grocery chain we find that individual stores employ more sales as the distance to wal mart falls moreover the increase in the frequency of sales was concentrated on the most popular products suggesting the use of a loss leader strategy

beyond dsge models toward an empirically based macroeconomics david colander has been writing about economic methodology for over 30 years but he goes out of his way to emphasize that he does not see himself as a methodologist his pragmatic methodology is applicable to what economists are doing and attempts to answer questions that all economists face as they go about their work the articles collected in this volume are divided with the first part providing a framework underlying colander s methodology and introducing colander s methodology for economic policy within that framework part two presents colander s view on the methodology for microeconomics while part three looks at colander s methodology for macroeconomics the book closes with discussions of broader issues this abstract was borrowed from another version of this item

the cyclicality of separation and job finding rates this paper uses cps gross flow data to analyze the business cycle dynamics of separation and job finding rates and to quantify their contributions to overall unemployment variability cyclical changes in the separation rate are negatively correlated with changes in productivity and move contemporaneously with them while the job finding rate is positively correlated with and tends to lag productivity contemporaneous fluctuations in the separation rate explain between 40 and 50 percent of fluctuations in unemployment depending on how the data are detrended this figure becomes larger when dynamic interactions between the separation and job finding rates are considered

technology shocks and job flows we consider a version of the solow growth model where technological progress can be investment specific or investment neutral the labour market is subject to search frictions and the existing productive units may fail to adopt the most recent technological advances technological progress can lead to the destruction of technologically obsolete jobs and cause unemployment we calibrate the model to replicate the high persistence that characterizes the dynamics of firms neutral technology and the frequency of firms capital adjustment we find that neutral technological advances increase job destruction and job reallocation and reduce aggregate employment investment specific technological advances reduce job destruction have mild effects on job creation and are expansionary hence neutral technological progress prompts schumpeterian creative destruction while investment specific technological progress operates essentially as in the standard neoclassical growth model using structural var models we provide support to the key dynamic implications of the model copyright 2007 wiley blackwell

unplanned purchases and retail competition i propose a framework in which consumers have biased beliefs about their future purchase probabilities leading them to make unplanned purchases us ing this framework i examine the phenomenon of below cost pricing and the welfare eects of banning it when the market is covered a ban on below cost pricing raises social surplus although consumers need not gain they are only guaranteed to ben et if the market is perfectly competitive when the market is not covered a ban always hurts at least some consumers also there is a pro competitive justica tion for the observation that larger rms sometimes charge below cost on the core product lines of smaller rms consumer bias is crucial for this justication multi product retailers sometimes sell certain products beneath cost with the hope of at tracting additional customers who will also buy other higher margin items this practice often referred to as loss leading is controversial with below cost pricing having been banned in a number of countries including belgium germany france and ireland and in approximately half of all us states 1 many us cities also have such prohibitions in this article i examine the welfare consequences of prohibitions on below cost pricing in a market where multi product retailers compete for boundedly rational consumers who practice one stop shopping that is visit at most one store when rivals are symmetric and the market is covered so that all consumers shop a ban on loss leading raises social surplus but when the market is not covered a ban presents a social welfare tradeo fewer consumers choose to shop although those who do generate higher levels of social surplus perhaps surprisingly for those consumers who shop both before and after a ban a ban is guaranteed to make them better o if the market is perfectly competitive but otherwise may harm them taken together these results indicate that it is simplistic to argue that by limiting the scope of competition below cost pricing bans must hurt consumers and society but i also assess below cost pricing laws in the presence of asymmetric competition as when a large rm with a full product line competes against a small rm with a limited product

the dynamic effects of aggregate demand and supply disturbances we interpret fluctuations in gnp and unemployment as due to two types of disturbances disturbances that have a permanent effect on output and disturbances that do not we interpret the first as supply disturbances the second as demand disturbances demand disturbances have a hump shaped mirror image effect on output and unemployment the effect of supply disturbances on output increases steadily over time peaking after two years and reaching a plateau after five years

modeling macroeconomies as open ended dynamic systems of interacting agents uall models are wrong but some are useful g e p box 1979 macroeconomists seek to understand the structure and performance of economies at a national or regional level and the manner in which government policymakers attempt to influence this structure and performance over time such understanding would seem to require a systematic exploration of the intricate feedback loops connecting micro behaviors interaction patterns and macro regularities as observed in real world economies

rules of thumb versus dynamic programming this paper studies decision making with rules of thumb in the context of dynamic decision problems and compares it to dynamic programming a rule is a fixed mapping from a subset of states into actions rules are compared by averaging over past experiences this can lead to favoring rules which are only applicable in good states correcting this good state bias requires solving the dynamic program we provide a generalframework and characterize the asymptotic properties we apply it to provide a candidate explanation for the sensitivity of consumption to transitory income jel eoo c63 c61 e21

technology policy interaction in frictional labour markets does capital embodied technological change play an important role in shaping labour market outcomes to address this question we develop a model with vintage capital and search matching frictions where irreversible investment in new vintages of capital creates heterogeneity in productivity among firms matched as well as vacant we demonstrate that capital embodied technological change reduces labour demand and raises equilibrium unemployment and unemployment durations in addition the presence of labour market regulations unemployment benefits payroll taxes and firing costs exacerbates these effects thus the model is qualitatively consistent with some key features of the european labour market experience relative to that of the u s it features a sharper rise in unemployment and a sharper fall in the vacancy rate and the labour share a calibrated version of our model suggests that this technology policy interaction could explain a sizeable fraction of the observed differences between the u s and europe copyright 2007 wiley blackwell

a dynamic theory of countervailing power in this article i develop a model of an infinitely repeated procurement auction with one buyer and several sellers the buyer can accumulate a backlog of unfilled orders which similar to a boom in demand forces the sellers to collude on a low price to prevent undercutting if the buyer s cost of shifiing its consumption over time is low enough then the extent of collusion is bounded away from the joint profit maximizing level even for discount factors approaching one the model is extended to allow for multiple buyers large buyers are shown to obtain lower prices from the sellers buyer mergers increase pro t for all buyers not just the merging pair at the expense of the sellers in contrast buyer growth through addition harms buyers that do not grow and benefits sellers

labor market dynamics and the business cycle structural evidence for the united states we use a 12 dimensional var to examine the aggregate effects of two structural technology shocks and two policy shocks for each shock we examine the dynamic effects on the labor market the importance of the shock for labor market volatility and the comovement between labor market variables and other key aggregate variables in response to the shock we document that labor market indicators display hump shaped responses to the identified shocks technology shocks and monetary policy shocks are important for labor market volatility but the ranking of their importance is sensitive to the var specification the conditional correlations at business cycle frequencies are similar in response to the four shocks apart from the correlations between hours worked labor productivity and real wages to account for the unconditional correlations between these variables a mixture of shocks is required

indivisible labor lotteries and equilibrium abstract this paper considers an economy where labor is indivisible and agents are identical although the discontinuity in labor supply at the individual level disappears as a result of aggregation it is shown that indivisible labor has strong consequences for the aggregate bahavior of the economy it is also shown that optimal allocations involve lotteries over employment and consumption

compatibility of regional and multilateral trading agreements reforming the wto process while the pillar of the world trade organization wto with respect to trade in goods services and intellectual property is nondiscrimination the cornerstone of regional trading agreements is discrimination 2 there has been a proliferation of regional trading agreements in recent years twenty nine new agreements have been notified to the general agreement on tariffs and trade gatt and the wto since 1992 27 on merchandise trade and two on trade in services this is almost half the number of agreements still in existence and notified to gatt prior to 1992 all but three wto members are parties to at least one regional agreement and some are parties to many more it is therefore not surprising that there is renewed interest in whether regional agreements compete with or complement the multilateral trading system 4 while there may be no clear answer it cannot be denied that recent regional developments have major implications for the rules based multilateral trading system one such development is that tariff preferences have or will become relatively unimportant in many regional trading agreements the reasons for this include the high proportion of trade outside many preferential agreements the limits to the coverage of the tariff preferences themselves the high share of post uruguay round tariffs that will be bound at zero and the low level of most favorednation mfn tariffs faced by non preferencereceiving countries this development is accompanied by the fact that the scope of application of many agreements has extended well beyond tariff preferences to disciplines that were traditionally the domain of gatt or may in the future be dealt with by the wto the european union eu provides a good example despite the numerous countries receiving tariff preferences its largest trading partners are outside the network of these agreements in fact 45 percent of eu imports originate in non preference receiving countries e g 17 percent in the united states and 10 percent in japan while tariff preferences are of considerable potential importance with the implementation of uruguay round commitments 51 percent of the value of imports from non preference receiving countries will enter the eu under bound duty free tariff rates further the trade weighted tariff average on manufactured imports from these countries will be 3 1 percent 6 development division world trade organization geneva switzerland helpful comments from maria pillinini of the wto are gratefully acknowledged as are those of richard snape of monash university and industries commission australia the views expressed in this article are those of the author and not the organization for which he works the wto came into existence on 1 january 1995 to inter alia facilitate the administration of the wto agreements that emerged from the uruguay round one of which is the revised 1947 general agreement on tariffs and trade i e gatt 1994b 2 unless otherwise specified the term regional trading agreements refers to both customs unions and free trade areas for trade in goods the extent of discrimination in regional agreements is related to the ease of accession of non parties and the openness of the agreements in general the three are japan korea and hong kong there were 128 members of gatt and following the completion of domestic ratification and wto accession procedures there will be approximately 160 members of the wto in the next few years there are presently 120 members 4 there are many excellent contributions to this debate see for example richard snape et al 1993 jagdish bhagwati 1995 and wto 1995 trade between the 15 members of the eu accounts for 60 percent of total eu trade the eu offers contractual preferences to 26 countries under free trade association or cooperation agreements and to 70 countries under the lom6 convention it offers noncontractual preferences to 145 countries under the generalized system of preferences gsp 6 while tariffs on agricultural products are generally higher than those on manufactured goods the agricultural sector is typically dealt with outside eu preferential agreements

a theory of the consumption function with and without liquidity constraints fifteen years ago milton friedman s 1957 treatise a theory of the consumption function seemed badly dated dynamic optimization theory had not been employed much in economics when friedman wrote and utility theory was still comparatively primitive so his statement of the permanent income hypothesis never actually specified a formal mathematical model of behavior derived explicitly from utility maximization instead friedman relied at crucial points on intuition and verbal descriptions of behavior although these descriptions sounded plausible when other economists subsequently found multiperiod maximizing models that could be solved explicitly the implications of those models differed sharply from friedman s intuitive description of his model furthermore empirical tests in the 1970s and 1980s often rejected these rigorous versions of the permanent income hypothesis in favor of an alternative hypothesis that many households simply spent all of their current income today with the benefit of a further round of mathematical and computational advances friedman s 1957 original analysis looks more prescient than primitive it turns out that when there is meaningful uncertainty in future labor income the optimal behavior of moderately impatient consumers is much better described by friedman s original statement of the permanent income hypothesis than by the later explicit maximizing versions furthermore in a remarkable irony much of the empirical evidence that rejected the permanent income hypothesis as specified in tests of the 1970s and 1980s is actually consistent both with friedman s original description of the model and with the new version with serious uncertainty there are four key differences between the explicit maximizing models

indivisible labor and the business cycle abstract a growth model with shocks to technology is studied labor is indivisible so all variability in hours worked is due to fluctuations in the number employed we find that unlike previous equilibrium models of the business cycle this economy displays large fluctuations in hours worked and relatively small fluctuations in productivity this finding is independent of individuals willingness to substitute leisure across time this and other findings are the result of studying and comparing summary statistics describing this economy an economy with divisible labor and post war u s time series

optimal consumption under uncertainty liquidity constraints and bounded rationality abstract i study how boundedly rational agents can learn a good solution to an infinite horizon optimal consumption problem under uncertainty and liquidity constraints using an empirically plausible theory of learning i propose a class of adaptive learning algorithms that agents might use to choose a consumption rule i show that the algorithm always has a globally asymptotically stable consumption rule which is optimal additionally i present extensions of the model to finite horizon settings where agents have finite lives and life cycle income patterns this provides a simple and parsimonious model of consumption for large agent based models

remittances entrepreneurship and employment dynamics over the business cycle abstract we incorporate remittances and micro entrepreneurship self employment into a small open economy business cycle model with capital and labor market frictions countercyclical remittances moderate the decline of households consumption during recessions these remittances also are used to finance the start up costs of microenterprises that bolster households income during economic downturns we show that the positive income effect from countercyclical remittances also leads to a decrease in salaried labor supply which generates offsetting upward pressure on wages during recessions and adversely affects the recovery of the economy consistent with the microeconomic evidence the behavior of remittances decisively affects labor force participation and the composition of employment between non salaried and salaried employment over the business cycle the model delivers labor market and aggregate cyclical dynamics that are consistent with the mexican data including a highly volatile and countercyclical unemployment rate

can long run restrictions identify technology shocks gali s innovative approach of imposing long run restrictions on a vector autoregression var to identify the effects of a technology shock has become widely utilized in this paper we investigate its reliability through monte carlo simulations using calibrated business cycle models overall gali s methodology appears to be fruitful the impulse responses derived from the artificial data generally have the same sign and qualitative pattern as the true responses and the approach can be informative in discriminating between alternative models however our results reveal some important quantitative shortcomings including considerable estimation uncertainty about the impact of technology shocks on macroeconomic variables more generally the conditions under which the methodology performs well appear considerably more restrictive than implied by the key identifying assumption this underscores the importance of using economic models to guide in the implementation of the approach in interpreting the results and in assessing its limitations jel c32 e32 o33

asymmetric volatility spillovers between uk regional worker flows and vacancies this paper investigates volatility spillovers between uk regional job finding job separation and vacancy rates employing a large bayesian logistic smooth transition vector autoregression var model we find high volatility spillovers between uk regional labour markets analyses of net spillovers show that in general shocks to job separation rates tend to spread into job finding and vacancy rates while vacancy rates are usually at the receiving end of shocks transmitted from the job separations and job findings to shed further light on the shock propagation mechanism we also look into more detailed matters such as the differences in spillovers between regions within the same regime and that of the same region but in different regimes

unemployment rate dynamics and persistent unemployment under rational expectations this paper develops a model of unemployment rate dynamics that provides an explanation of persistent cyclical unemployment that does not involve persistent expectational errors or other nonoptimizing behavior our results are based on the interaction of search dynamics and inventory adjustments an important element in these dynamics appears to be heterogeneity in the labor force which can be characterized as consisting of a relatively small group of high turnover individuals who comprise the bulk of normal unemployment and a larger group of low turnover individuals who dominate movements in cyclical unemployment our empirical results provide support for this theory as we demonstrate that the appropriately measured probability of becoming employed during a recovery falls relative to normal because of the unusually high proportion of low turnover individuals who have lost permanent jobs as aresult recovery is much slower than is indicated by normal relationships although each individual is searching optimally this abstract was borrowed from another version of this item

a near rational model of the business cycle with wage and price inertia this paper presents a model in which insignificantly suboptimal behavior causes aggregate demand shocks to have significant real effects the individual loss to agents with inertial price wage behavior is second order in terms of the parameter describing the shock while the effect on real economic variables is first order thus significant changes in business activity can be generated by anticipated money supply changes provided that some agents are willing to engage in nonmaximizing behavior which results in small losses

bilateral monopolies and incentives for merger the paper presents a model of duopoly in which firms acquire inputs through bilateral monopoly relations with suppliers it combines a bargaining model with a duopoly model to examine how input pri

the loss leader is a turkey targeted discounts from multi product competitors abstract i show that multi product firms can compete for their more profitable customers by setting lower margins on goods that are purchased primarily by them effectively offering them discounts without offering these discounts to less profitable customers this suggests a theory of multi product pricing in which a good s profit margin is inversely related to the profitability of the customers who purchase it this theory i provides one explanation for firms offering lower prices to larger customers and ii suggests that loss leader pricing may allow firms to compete more vigorously for more profitable customers this can explain why stores sell turkeys as loss leaders at thanksgiving but may not discount flowers on mother s day or candy on valentines day

volatility and welfare abstract this paper explores the relationship between volatility and welfare even though households prefer smooth streams of consumption and leisure welfare can be increasing in the volatility of an exogenous driving force if factor supply is sufficiently elastic we provide some analytical results for a model without capital and do some quantitative exercises in a model with capital and a variety of shocks welfare is greater in high shock volatility regimes under plausible parameter values augmenting the model with features that increase the elasticity of factor supply extends the range of parameters over which higher volatility results in greater welfare

factor complementarity and labour market dynamics abstract we propose and estimate a dynamic stochastic general equilibrium model featuring search and matching frictions deep habits and a ces production function the model successfully replicates the cyclical properties of labour market variables in the us economy for three main reasons first two of the endogenous mechanisms of the model factor complementarity and unemployment benefits play a key role for explaining the amplification in unemployment and vacancies second deep habits have a smaller but significant role as an endogenous mechanism third capital augmenting productivity investment specific and matching efficiency innovations explain large part of the variation in labour market variables

beyond microfoundations towards a not too rational macroeconomics at ucla we are establishing a center for computable economics i have been very much involved in this effort this may surprise you that a non mathematical macro monetary economist should become an enthusiast for this project is one of those things that do not compute but then as i will explain we take a special interest in things that do not compute one may come to computable economics by many intellectual routes i will trace my own not because it makes a particularly edifying story but because it will tell you what kind of problems i hope we can make progress on by developing the field of computable economics but before we get to that i had better explain what i mean by computable economics

investment shocks and business cycles abstract the origins of business cycles are still controversial among macroeconomists this paper contributes to this debate by studying the driving forces of fluctuations in an estimated new neoclassical synthesis model of the u s economy in this model most of the variability of output and hours at business cycle frequencies is due to shocks to the marginal efficiency of investment imperfect competition and to a lesser extent technological frictions are the key to their transmission although labor supply shocks explain a large fraction of the fluctuations in hours at very low frequencies they are irrelevant over the business cycle this finding is important because the microfoundations of these disturbances are widely regarded as unappealing

the emergence of economic organization abstract a model of decentralized markets is studied in which transactors follow simple adaptive rules transactions are coordinated by specialist trading firms that bear the costs of market disequilibrium starting from an initially autarkic situation in which none of the institutions that support exchange exist computer simulation shows that for a wide range of parameter values a fully developed market economy will emerge spontaneously moreover in virtually every case where a market economy develops one of the commodities traded will emerge as a universal medium of exchange being traded by every firm and changing hands in every act of exchange

trend breaks long run restrictions and contractionary technology improvements abstract structural vector autoregressions with long run restrictions are extraordinarily sensitive to low frequency correlations recent literature finds that the estimated effects of technology shocks are sensitive to how one treats hours per capita however after allowing for statistically and economically significant trend breaks in productivity results are much less sensitive hours fall when technology improves the issue is that the common high low high pattern of productivity growth and hours i e the low frequency correlation inevitably leads to a positive estimated response the trend breaks control for this correlation this example suggests a practical need for care in using long run restrictions

adaptive consumption behavior abstract in this paper we propose and study a theory of adaptive consumption behavior under income uncertainty and liquidity constraints we assume that consumption is governed by a linear function of wealth whose coefficients are revised each period by a procedure that places few informational or computational demands on the consumer we show that under a variety of settings the procedure converges quickly to a set of coefficients with low welfare cost relative to a fully optimal nonlinear consumption function

decentralized dispersed exchange without an auctioneer abstract we stimulate exchange among geographically dispersed agents who face real costs of communication along with bounds to rationality and calculation exchange is entirely decentralized it is initiated by individual agents who broadcast costly messages indicating their interest in trade it is accomplished by bilateral bargaining between pairs of agents agents use the information gained from previous attempts at local trade to calculate their search strategies for succeeding rounds this decentralized mechanism can achieve a substantial improvement in the allocation of resources and the average welfare of agents in comparison with a randomized initial endowment but in comparison with walrasian equilibrium agents who begin with endowments of equal value end up with substantially unequal wealth although the initial inequality of utility is reduced

slow to hire quick to fire employment dynamics with asymmetric responses to news this paper studies models of rms that adjust asymmetrically to private signals and uses census data to assess predictions at the establishment level when rms hiring decisions respond more to bad signals than to good signals both aggregate volatility and the cross sectional dispersion of employment growth are countercyclical responses to measured technology shocks and the time series behavior of skewness are consistent with the mechanism even in the absence of physical adjustment costs and with homoskedastic shocks to fundamentals information processing under knightian uncertainty generates asymmetric adjustment

price stickiness in ss models new interpretations of old results abstract what is the relation between infrequent price adjustment and the dynamic response of the aggregate price level to monetary shocks the answer to this question ranges from a one to one link calvo g 1983 prices in a utility maximizing framework journal of monetary economics 12 383 398 to no connection whatsoever caplin a spulber d 1987 menu costs and the neutrality of money quarterly journal of economics 102 703 726 the purpose of this paper is to provide a unified framework to understand the mechanisms behind this wide range of results in doing so we propose new interpretations of key results in this area which in turn suggest the kind of ss model that is likely to generate substantial price rigidity among these new interpretations we revisit caplin and spulber s monetary neutrality result we show that when price stickiness is measured in terms of the impulse response function this result is not a consequence of aggregation as is often assumed but is due instead to the absence of price stickiness at the microeconomic level we also show that the selection effect according to which units that adjust their prices are those that benefit the most is neither necessary nor sufficient to account for the higher aggregate flexibility of ss type models compared to calvo models instead the key concept is the contribution of the extensive margin of adjustment to the aggregate price response the aggregate price level is more flexible than suggested by the microeconomic frequency of adjustment if and only if this term is positive

optimal irrational behavior abstract contrary to the usual presumption that welfare in markets is maximized if consumers behave rationally we show in a two period overlapping generations model that there always exists an irrational consumption rule that can weakly improve upon the lifecycle permanent income rule in general equilibrium the market clearing mechanism introduces a pecuniary externality that individual rational households do not consider when making decisions but a publically shared rule of thumb can exploit for typical calibrations the improvement of the welfare of irrational households is robust to the introduction of rational agents although transitions to the optimal irrational steady state are not pareto improving transitions do exist that will improve a pareto social welfare function with a sufficiently small generational discount rate generalizing to a more realistic lifecycle model we find that the save more tomorrow smart plan if properly parameterized can confer higher lifetime utility than the permanent income rule

an alternative explanation of the price puzzle abstract this paper proposes an explanation for the frequent appearance of a price puzzle in vars designed for monetary policy analysis it assumes that the data are generated by a model in which output and output gap are not equivalent while an econometrician follows the common practice of including only output in the var the omission of the output gap is shown to spuriously produce a price puzzle and several other incorrect conclusions in a class of commonly used models this can happen even if the model admits a triangular identification and if the forecasts produced by the misspecified var are optimal when the model is tested on us data all predictions are supported a commodity price index is not needed to solve the puzzle

interest rate control and nonconvergence to rational expectations this paper investigates the feasibility of a monetary policy aimed at pegging the nominal rate of interest it shows that under general conditions such a policy would produce the well known cumulative process despite the fact that there exists a well behaved rational expectations equilibrium with no tendency for inflation to accelerate or decelerate the cumulative process shows up as the failure of learning to converge to rational expectations specifically the paper shows first in a conventional is lm model with an expectations augmented phillips curve and then in a micro based finance constraint model that if people follow any learning rule based on experience that satisfies a weak condition then the sequence of temporary equilibria under a policy of interest pegging cannot converge the nonconvergent path that will be observed accords with the familiar cumulative process in that inflation accelerates if the market rate of interest has been pegged below the natural rate

the ins and outs of unemployment an analysis conditional on technology shocks we analyze how unemployment job finding and job separation rates react to neutral and investment specific technology shocks neutral shocks increase unemployment and explain a substantial portion of it volatility investmentspecific shocks expand employment and hours worked and contribute to hours worked volatility movements in the job separation rates are responsible for the impact response of unemployment while job finding rates for movements along its adjustment path the evidence warns against using models with exogenous separation rates and challenges the conventional way of modelling technology shocks in search and sticky price models

introducing the all seeing eye of business a model for understanding the nature impact and potential uses of waste abstract at current rates of disposal there are nearly 8 years of remaining landfill capacity at permitted sites in england and wales industry encouraged by financial penalties from the government faces the challenges of cleaner and more sustainable production whilst trying to remain competitive in the market place this paper proposes fit thinking as a means by which waste can be reduced from the early design stages alongside the all seeing eye of business a model to illustrate potential sources of profit and loss in a manufacturing firm s output a literature review on waste and profitability reveals the basis for the model concepts from material flow cost accounting the kanthal effect and the kano model are combined together with industry case studies to develop the model the model is explained in detail demonstrating twelve types of relationships between a company s product outputs and the profitability of each output the model and the relationships it proposes are then tested against examples from literature ultimately fit thinking is shown to help companies prevent waste where waste is unavoidable the all seeing eye of business model can be used by companies in the understanding of their non product output waste providing insights into the nature of their waste and the impact on profitability it is hoped that this understanding will encourage them to see waste as a potential profit making co product rather than as a necessary evil

multiproduct pricing in oligopoly abstract this paper proposes a two good model of price competition where some consumers visit all shops and others visit only one we find that information frictions lead to price dispersion when the two goods are complements their prices will tend to be negatively correlated so if one is priced high the other will be discounted this finding is supported by some empirical evidence which suggests that simultaneous price discounts of complements are infrequent if the goods are substitutes their prices will be uncorrelated potentially rationalizing the lack of evidence on their co pricing when selling complements retailers earn higher profits than in the one good model through taxing captive consumers with a high overall price tag and attracting shoppers by pricing one of the goods aggressively bundling practices are thus shown to be detrimental to retailers profits

shocks versus responsiveness what drives time varying dispersion the dispersion of many economic variables is countercyclical what drives this fact greater dispersion could arise from greater volatility of shocks or from agents responding more to shocks of con

does the new economy measure up to the great inventions of the past abstract during the four years 1995 99 u s productivity growth experienced a strong revival and achieved growth rates exceeding that of the golden age of 1913 72 accordingly many observers have declared the new economy to be an industrial revolution even more important than the second industrial revolution of 1860 1900 which made the golden age of productivity growth possible this paper dissects the recent productivity revival subtracts out a cyclical component and concludes that there is no revival of the productivity growth trend in the 88 percent of the private economy lying outside of the durables manufacturing sector the paper explains this surprising finding by pointing to limitations in computers and the internet in comparison with the great inventions of the past

u s labor market dynamics revisited the picture of u s labor market dynamics is opaque empirical studies have yielded contradictory findings and debates have emerged regarding their implications this paper aims at clarifying the picture which is important for the understanding of the operation of the labor market for the study of business cycles for the explanation of wage behavior and for the formulation of policy the paper determines what facts can be established what are their implications and what remains to be further investigated the main contributions made here are i listing of data facts that can be agreed upon these indicate that there is considerable cyclicality and volatility of both accessions to employment and separations from it hence both are important for the understanding of the business cycle ii presenting the business cycle facts of key series iii pointing to specific gaps in the data picture disparities in the measurement of the sizeable flows between employment and the pool of workers out of the labor force disagreements about the relative volatility of job finding and separation rates across data sets and the fact that the fit of the gross flows data with net employment growth data differs across studies and is not high the definite characterization of labor market dynamics depends upon the closing of these data gaps

productivity shocks and real business cycles abstract productivity shocks play a central role in real business cycles as an exogenous impulse to macroeconomic activity however measured solow prescott residuals do not behave as an exogenous impulse rather econometric evidence provided in this paper indicates that 1 money interest rates and government spending granger cause these impulses and 2 a substantial component of the variance of these impulses between one quarter and one half is attributable to variations in aggregate demand these results are robust to a number of econometric issues including measurement errors specification of the production function and certain forms of omitted real variables

on the timing and efficiency of creative destruction we analyze the timing pace and efficiency of ongoing job reallocation that results from product and process innovation there are strong reasons why an efficient economy ought to concentrate both job creation and destruction during recessions when the opportunity cost of reallocation is lowest incomplete contracting between labor and capital can disrupt this synchronized pattern and decouple creation and destruction transactional difficulties also lead to technological sclerosis characterized by excessively slow renovation government incentives to production may alleviate high unemployment but exacerbate sclerosis in contrast creation incentives increase the pace of reallocation an optimal combination of both policies restores economic efficiency

can more consumers lead to lower profits a model of multi product competition abstract the article analyzes the optimal pricing strategy of duopoly retailers who sell two goods to three consumer segments two segments that are interested in one good and one that wants to buy both goods the analysis suggests that the markup on one of the goods might be negative and that the existence of consumers who buy both goods can either increase or decrease markups surprisingly the addition of the consumers who buy both goods unchanging the number of the other consumers might decrease profits and increasing the number of consumers who buy one good might also reduce profits this suggests that firms should consider carefully how additional customers might affect the competitive environment and the equilibrium before attempting to attract them to the market

loss leader pricing and rain check policy loss leader pricing and rain check policies are common in retail markets yet research on these topics is surprisingly scarce in this paper we study the effects of leader pricing and rain check policy on stores profits and market outcomes suppose stores can accurately predict demand might they still run out of stock we investigate whether such a result is plausible when stores can offer rain checks the paper also helps resolve an issue that has recently attracted much attention should the ftc repeal its rule prohibiting stock outs of advertised sale items

do technology shocks lead to a fall in total hours worked this paper contributes to the debate initiated by gali in 1999 i provide a theory with capital income taxation labor hoarding as well as long run shifts in the social attitudes to the workplace modelled as leisure at the workplace to argue that there are other shocks that may influence labor productivity in the long run i introduce medium run identification and show it to be superior to long run identification or standard short run identification when applied to artificial data with u s data and medium run identification i find the robust result that technology shocks lead to a hump shaped response of total hours worked which is mildly positive following a near zero initial response jel e32 e24 c32 c15 copyright c 2004 the european economic association

unemployment and the labor share abstract the labor share fluctuates over the business cycle to explain this behavior we develop a novel model featuring direct competition between heterogeneous firms to hire workers this simultaneously endogenizes both average match productivity and the division of output between workers and firms in existing matches wages partly reflect labor market conditions at the time of hiring a positive tfp shock therefore reduces the aggregate labor share making it counter cyclical however greater competition and lower unemployment increase labor s share among new firms as more firms enter the aggregate labor share rises and eventually overshoots its initial level as in the data

small menu costs and large business cycles a macroeconomic model of monopoly i introduction the conflict between modern neoclassical and traditional keynesian theories of the business cycle centers upon the pricing mechanism in neoclassical models prices are fully flexible they represent the continuous optimization of economic agents and the continuous intersection of supply and demand in keynesian models prices are often assumed to be sticky they do not necessarily equilibrate all markets at all times one of the reasons for the resurgence of the equilibrium approach to macroeconomics has been the absence of a theoretical underpinning for this keynesian price stickiness this note shows that sticky prices can be both privately efficient and socially inefficient the business cycle results from the suboptimal adjustment of prices in response to a demand shock to the extent that policy can stabilize aggregate demand it can mitigate the social loss due to this suboptimal adjustment in some keynesian models prices are simply exogenously fixed 2 in others agents must set their prices in advance of the transaction date the act of altering a posted price is certainly costly these costs include such items as printing new catalogs and informing salesmen of the new price yet these menu costs are small and therefore generally perceived as providing only a weak foundation for these fixed price models however this inference is flawed small menu costs can cause large welfare losses the claim that price adjustment costs are small does not rebut the claim that they are central to understanding economic fluctuations

the sensitivity of tests of the intertemporal allocation of consumption to near rational alternatives suppose a consumer sets consumption equal to income each period rather than following the optimal permanent income decision rule how much utility does he lose this paper finds that the answer is typically less than 10 cents 1 per quarter in environments specified by popular tests on aggregate data it includes calculations of the costs of excess sensitivity and excess smoothness to income and interest rate changes and the costs of ignoring information it concludes that the theory does not make predictions for aggregate tests that are robust to small costs such as information or transactions copyright 1989 by american economic association

volatility and development why is gdp growth so much more volatile in poor countries than in rich ones we identify four possible reasons i poor countries specialize in more volatile sectors ii poor countries specialize in fewer sectors iii poor countries experience more frequent and more severe aggregate shocks e g from macroeconomic policy and iv poor countries macroeconomic fluctuations are more highly correlated with the shocks of the sectors they specialize in we show how to decompose volatility into these four sources quantify their contribution to aggregate volatility and study how they relate to the stage of development we document the following regularities first as countries develop their productive structure moves from more volatile to less volatile sectors second the level of specialization declines with development at early stages and slowly increases at later stages of development third the volatility of country specific macroeconomic shocks falls with development fourth the covariance between sector specific and country specific shocks does not vary systematically with the level of development we argue that many theories linking volatility and development are not consistent with these findings and suggest new directions for future theoretical work

why do larger buyers pay lower prices intense supplier competition abstract the paper provides a theoretical explanation of the common claim that larger buyers pay lower prices in the model suppliers compete more aggressively for the business of larger buyers much as they do in boom periods of rotemberg and saloner

technological acceleration skill transferability and the rise in residual inequality this paper provides a quantitative theory for the recent rise in residual wage inequality consistent with the empirical observation that a sizable part of this increase has a transitory nature a feature that eludes standard models based on ex ante heterogeneity in ability an acceleration in the rate of quality improvement of equipment like the one observed from the early 1970s increases the productivity quality differentials across machines jobs in a frictional labor market this force translates into higher wage dispersion even among ex ante equal workers with vintage human capital the acceleration reduces workers capacity to transfer skills from old to new machines generating a rise in the cross sectional variance of skills and therefore of wages through calibration the paper shows that this mechanism can account for 30 percent of the surge in residual inequality in the u s economy or for most of its transitory component two key implications of the theory faster within job wage growth and larger wage losses upon displacement find empirical support in the data

the dynamic effects of neutral and investment specific technology shocks the neoclassical growth model is used to identify the short run effects of neutral technology shocks which affect the production of all goods homogeneously and investment specific shocks which affect only investment goods the real equipment price crucial for identifying the investment shocks experiences an abrupt increase in its average rate of decline in 1982 so the analysis is based on a split sample on the basis of the preferred specification the two technology shocks account for 73 percent of hours and 44 percent of output s business cycle variation before 1982 and 38 percent and 80 percent afterward the shocks also account for more than 40 percent of hours and 58 percent of output s forecast errors over a three to eight year horizon in both samples the majority of these effects are driven by the investment shocks

the cleansing effect of recessions the authors investigate industry response to cyclical variations in demand production units that embody the newest process and product innovations are continuously being created and outdated units are being destroyed although outdated units are the most likely to turn unprofitable and be scrapped in a recession they can be insulated from the fall in demand by a reduction in creation the structure of adjustment costs plays a determinant role in the responsiveness of those two margins the calibrated model matches the relative volatilities of the observed manufacturing job creation and destruction series and their asymmetries over the cycle copyright 1994 by american economic association

the effects of technology shocks on hours and output a robustness analysis we analyze the effects of neutral and investment specific technology shocks on hours and output long cycles in hours are removed in a variety of ways hours robustly fall in response to neutral shocks and robustly increase in response to investment specific shocks the percentage of the variance of hours output explained by neutral shocks is small large the opposite is true for investment specific shocks news shocks are uncorrelated with the estimated technology shocks copyright 2009 john wiley sons ltd

on the concavity of the consumption function at least since keynes 1935 many economists have had the intuition that the marginal propensity to consume out of wealth declines as wealth increases nonetheless standard perfect certainty and certainty equivalent versions of intertemporal optimizing models of consumption imply a marginal propensity to consume that is unrelated to the level of household wealth we show that adding income uncertainty to the standard optimization problem induces a concave consumption function in which as keynes suggested the marginal propensity to consume out of wealth or transitory income declines with the level of wealth

a structural equations analysis of the impact of price promotions on store performance guided by past research conventional wisdom in the retailing area and microeconomic theory the authors develop a series of hypotheses about the effects of loss leaders in store price specials