search layoffs and reservation wages i analyze job search models with random layoffs in which employment opportunities are characterized by a wage and some measure of risk intuition suggests that a worker ought to demand a higher wage if he is to accept a job with a higher layoff rate but this is not true in several models analyzed in the literature i demonstrate here that assumptions about what happens immediately after a layoff and after a quit are critical in determining the relation between reservation wages and risk making these assumptions explicit clarifies the reasons why different models imply quite different predictions

nonlinearities in economic dynamics two reasons that led to the dominance of the linear stochastic difference equations approach the first one was the fact that the nonlinear systems seemed incapable of reproducing the statistical aspects of actual economic time series at best such models were able to produce periodic motion1 and an examination of the spectra of economic time series showed the absence of the spikes that characterise periodic data the emphasis on the equilibrium approach to aggregate economic behaviour cf lucas i 986 would make things even more difficult the plethora of stability results for models of infinitely lived agents with perfect foresight turnpike theorems suggested that even the regular fluctuations that had been derived in the literature on endogenous business cycles were incompatible with a theory that had solid microeconomic foundations further this indicated that while nonlinearities could be present the explanations of the fluctuations had to rest solely on the presence of exogenous shocks that working through the equilibrating mechanism would create the observed randomness if such shocks were absent the system would tend to a stationary state the second reason was the empirical success of the models based on linear stochastic difference equations low order autoregressive processes captured some of the features of aggregate time series in turn these processes can in principle result from an economy with complete markets where production is subject to exogenous shocks though the task of confronting these equilibrium models with actual data has not yielded uncontroversial results see the discussion and references in section i there was no obvious gain in the

behavioural attitudes towards water saving evidence from a study of environmental actions given the growing emphasis being placed on water conservation in and around the home by water companies there is a pressing need to identify the characteristics of the water saver so that policy makers can more accurately target initiatives for water conservation this paper examines the social attitudinal and behavioural composition of water saving activities using a sample of 1600 households from devon the research sought to examine the links between water saving energy conservation green consumerism and waste management in and around the home accordingly the extent to which water saving can be placed within a behavioural context that incorporates different environmental behaviours is discussed the data relating to water saving are then analysed and four different types of individual are defined according to their behavioural characteristics these are examined in the context of their demographic composition and a range of attitudinal factors the policy implications of the research are described throughout the paper

sectoral shocks and aggregate fluctuations abstract this paper presents a multisector dynamic general equilibrium model of business cycles with a distinctive feature aggregate fluctuations are driven by independent sectoral shocks the model hypothesizes that trade among sectors provides a strong synchronization mechanism for these shocks due to the limited but locally intense interaction that is characteristic of such input trade flows limited interaction characterized by a sparse intermediate input use matrix reduces substitution possibilities among intermediate inputs which strengthens comovement in sectoral value added and leads to a postponement of the law of large numbers in the variance of aggregate value added the chief virtue of this model is that reliance on implausible aggregate shocks is not necessary to capture the qualitative features of macroeconomic fluctuations building on horvath 1998 review of economic dynamics 1 781 808 which establishes the theoretical foundation for the relevance of limited interaction in the context of a stylized multisector model this paper specifies a more general multisector model calibrated to the us 2 digit standard industrial code economy simulations prove the model is able to match empirical reality as closely as standard one sector business cycle models without relying on aggregate shocks

unemployment insurance taxes and unemployment unemployment insurance is financed by a tax on wages below a given ceiling daniel s hamermesh 1977 advocates raising this ceiling on distributional grounds in a job search model this does decrease unemployment among low wage workers but also increases unemployment among high wage workers and lowers everyone s expected after tax wage an increase in the ceiling combined with a proportionate reduction in the tax rate decreases unemployment for low wage workers while increasing their after tax wage without affecting high wage workers at all when unemployment benefits and wages are taxed at one rate employment and wages are independent of that rate

privately operated water utilities municipal price negotiation and estimation of residential water demand the case of france this paper addresses the issue of price negotiation between a municipality and a private water utility operator and its implications for residential water demand estimation we use appropriate econometric procedures to estimate a water demand equation on a panel of french municipalities we find evidence that negotiated water price depends on municipality s characteristics causing endogeneity of price in the demand equation the impact of average household income housing and system features such as metering is investigated both on municipal consumption and price estimated price and income elasticities are significant and close to previous household level studies

macroeconomics after the crisis time to deal with the pretense of knowledge syndrome the recent financial crisis has damaged the reputation of macroeconomics largely for its inability to predict the impending financial and economic crisis to be honest this inability to predict does not concern me much it is almost tautological that severe crises are essentially unpredictable for otherwise they would not cause such a high degree of distress what does concern me about my discipline is that its current core by which i mainly mean the so called dynamic stochastic general equilibrium approach has become so mesmerized with its own internal logic that it has begun to confuse the precision it has achieved about its own world with the precision that it has about the real one this is dangerous for both methodological and policy reasons to be fair to our field an enormous amount of work at the intersection of macroeconomics and corporate finance has been chasing many of the issues that played a central role during the current crisis including liquidity evaporation collateral shortages bubbles crises panics fire sales risk shifting contagion and the like however much of this literature belongs to the periphery of macroeconomics rather than to its core i will discuss the distinction between the core and the periphery of macroeconomics as well as the futile nature of the integrationist movement that is the process of gradually bringing the insights of the periphery into the dynamic stochastic general equilibrium structure i argue that the complexity of macroeconomic interactions limits the knowledge we can ever attain and that we need to place this fact at the center of our analysis we should consider what this complexity does to the actions and reactions of the economic agent and seek analytical tools and macroeconomic policies that are robust to the enormous uncertainty to which we are confined

search theoretic models of the labor market a survey we survey the literature on search theoretic models of the labor market we show how this approach addresses many issues including the following why do workers sometimes choose to remain unemployed what determines the lengths of employment and unemployment spells how can there simultaneously exist unemployed workers and unfilled vacancies what determines aggregate unemployment and vacancies how can homogeneous workers earn different wages what are the tradeoffs firms face from different wages how do wages and turnover interact what determines efficient turnover we discuss various modeling choices concerning wage determination and the meeting process including recent models of directed search

perspective from gaussian to paretian thinking causes and implications of power laws in organizations although normal distributions and related current quantitative methods are still relevant for some organizational research the growing ubiquity of power laws signifies that pareto rank frequency distributions fractals and underlying scale free theories are increasingly pervasive and valid characterizations of organizational dynamics when they apply researchers ignoring power law effects risk drawing false conclusions and promulgating useless advice to practitioners this is because what is important to most managers are the extremes they face not the averages we show that power laws are pervasive in the organizational world and present 15 scale free theories that apply to organizations next we discuss research implications embedded in pareto rank frequency distributions and draw statistical and methodological implications

weak instruments diagnosis and cures in empirical econometrics what is the weak instruments wi problem and what causes it universal agreement does not exist on these questions we define weak instruments by two features i two stage least squares 2sls analysis is badly biased toward the ordinary least squares ols estimate and alternative unbiased estimators such as limited information maximum likelihood liml may not solve the problem and ii the standard first order asymptotic distribution does not give an accurate framework for inference thus a researcher may estimate bad results and not be aware of the outcome the cause of wi is often stated to be a low r or f statistic of the reduced form equation in the most commonly occurring situation of one right handside endogenous variable we find the situation is more complex with an additional factor the correlation between the stochastic disturbances of the structural equation and the reduced form that needs to be taken into account we discuss in this paper a specification test hahn and hausman 2002a for wi a caution against using no moments estimators such as liml in the wi situation and suggestions for different estimators an approach to inference of frank kleibergen 2002 for wi we end with a caution of how small biases can become large biases in the wi situation we begin with the limited information structural model under the assumptions of hausman 1983

job security and job search in more than one labor market i introduction a person looking for a new job faces a choice not only of which jobs to accept but where to search for a job in this connection differences in job security across sectors of the economy would appear to be a major concern of many workers however job security has not found a commensurate place in the literature on job search largely due to the single sector orientation of standard search models this paper analyzes the optimal search behavior of unemployed workers who may search in two distinct labor markets or sectors of the economy it is shown that the optimal policy assigns the same reservation wage but different search intensities in each sector the search literature has generally assumed that a worker searches for a job in a single labor market jobs differ from each other once found but while searching all jobs look the same to a worker until an offer is made in this context jobs with higher layoff rates have been shown to induce higher lower or no different reservation wages than similar jobs with lower layoff rates depending upon the specifics of the models which are not compelling examples include burdett and mortensen 1980 hey and mavromaras 1981 ioannides 1981 sargent 1987 and wright 1986 1987 despite our intuitions these studies provide no strong suggestion that a worker will be more likely to become employed in a type of job which offers greater job security all else equal it is otherwise in a multi sector world while the reservation wages associated with the two sectors of the economy are equal despite differences in layoff rates a worker will search more intensively in the sector with a lower layoff rate ii the model the model is simple the worker maximizes his expected wealth in a continuous time stationary environment over an infinite time horizon there are two sectors a and b each is characterized by a permanent layoff rate an offer arrival rate and a wage offer distribution the model generalizes the standard search paradigm and generalizes easily to n sectors accordingly familiar derivations will be omitted they can be found in fallick 1990 an unemployed worker may search for a job in either or both of the sectors simultaneously he pays search costs depending upon how much he searches in total the worker may not search while employed and there is no possibility of being recalled to a previous job the worker may move from unemployment to employment in either sector by receiving and accepting a wage offer from that sector wage offers from sector j j a b are random variables drawn independently from a constant exogenous distribution function f sup j w offers expire immediately if not accepted an employed worker may move from employment in either sector to unemployment by being laid off every job in a sector has the same layoff rate an employed worker never quits it would never be optimal to quit anyway assume that the instantaneous probability of receiving a job offer from sector j is equal to alpha sub j sigma s sub j where alpha sub j the offer arrival rate is the exogenous instantaneous probability that an offer from sector j arrives during the period the term alpha sub j is constant over time the term sigma s sub j is a function of the intensity with which the worker searches in sector j while unemployed normalize the total amount of search intensity available at any one time to unity so that s sub a s sub b is less than or equal to 1 let sigma center dot be an increasing concave function with sigma 0 0 sigma 1 1 sigma prime 0 infinity and sigma prime 1 0 the instantaneous probability of a permanent lay off from a job in sector j is lambda sub j there is a constant marginal cost of searching c assume that job offers and layoffs are generated by constant poisson processes in standard fashion the instantaneous probability of receiving more than one offer simultaneously vanishes

demand specification for municipal water management evaluation of the stone geary form to specify demand in most water allocation problems researchers face a tradeoff between flexibility and parsimony flexible forms are less constraining on elasticity estimates but require large parameter sets that tend to cause poor out of sample forecasts and computational difficulties using a five year panel of texas municipalities the parsimonious stone geary form yields estimated demand functions that are comparable to flexible form results the stone geary specification also provides an estimate of the portion of water use that may not be responsive to price and is useful in analysing price structures and designing conservation policies

alternate price specifications for estimating residential water demand with fixed fees using a new model formulation and data from a sample of colorado utilities we investigated the price specification controversy marginal price versus average revenue when estimating residential water demand the improved statistical fit using average revenue as the price variable was shown to be an artifact of the unitary elastic identity created when monthly rate schedules contain a fixed fee when the fixed fee was purged from the data average price was not significant but marginal price remained significant in the preferred double log marginal price model estimated price elasticity was 0 3 and conservation programs had no significant effect on water use

long run study of residential water consumption the estimation of dynamic models and themeasure of long run effects arerare in residential water demand studies weshow in this paper that a dynamicmodel of water consumption can be derived froma structural optimisation programsolved by local communities thisnonlinear model is estimated on asample of french municipalities and is foundasymptotically equivalent to a dynamic panel data model that is linear in theparameters the latter includes anoriginal error component structure that allowsfor a flexible heterogeneity pattern including both the usual idiosyncraticeffect and an additional individualeffect affected by a multiplicative time varyingparameter as usual gmm estimators for panel data are not consistent inthis case we propose a new gmmprocedure that yields consistent and efficientestimates of short and long runprice elasticities respectively 0 26 and 0 40

self organized criticality and economic fluctuations economists have long been interested in explaining the observed instability of economic aggregates though several reasons for variation in the pace of production are easily given such as exogenous variation in tastes or in production possibilities it is hard to see why there should be large variations in those factors that are synchronized across the entire economy instead it seems more likely to suppose that variations in demand or in production costs in different parts of the economy should be largely independent and hence that a law of large numbers would imply that significant variations in aggregate activity relative to the typical size of aggregate activity are not likely to occur an alternative approach proposes that economies possess intrinsically unstable dynamics which even in the absence of external shocks would result in persistent deterministic fluctuations this type of model implies however that aggregate fluctuations should involve motion on a low dimensional attractor while analysis of economic time series has not revealed structure of this kind another alternative proposes that the economy possesses multiple equilibria and that it can therefore switch between equilibria for arbitrary reasons this possibility suffers however from the difficulty that one must explain how people succeed in coordinating their expectations about the times at which a shift should occur here we explore another type of explanation which relies on an entirely different mechanism our proposal is that the effects of many small independent shocks to different sectors of the economy need not cancel out in the aggregate due to the presence of significantly nonlinear strongly localized interactions between different parts of the economy the type of macroscopic instability that can result has been studied by condensed matter physicists under the name of self organized criticality per bak and kan chen 1991 physicists have noted in several contexts the possibility of a critical state in which independent microscopic fluctuations can propagate so as to give rise to instability on a macroscopic scale this is a state in which chain reactions initiated by local disturbances neither damp out over a short distance the subcritical case nor propagate explosively so that the system cannot remain in that state the supercritical case as in the controlled nuclear fission that allows a reactor to generate power without exploding often this has seemed to depend upon parameters being carefully tuned to exactly their critical values in the case of a reactor an elaborate control mechanism is required to keep it near criticality more recently it has been argued that some systems may spontaneously evolve toward a critical state and return to it even if perturbed by an external shock the prototypical example of such selforganized criticality is a sandpile when the slope of the pile is nowhere too steep dropping on additional grains of sand at randomly chosen sites has no macroscopic effects as at most small numbers of grains will shift position in each case however randomly dropping on additional sand will eventually result in the slope of the pile increasing to a critical slope at which point large avalanches can occur in response to the dropping of a single additional grain of sand a sandpile with a slope that is initially greater than the critical slope also evolves toward it in this case through an immediate department of economics university of chicago 1126 east 59th st chicago il 60637 we thank per bak buz brock boyan jovanovic and paul krugman for discussions and the santa fe institute and the nsf for research support 1scheinkman 1990 surveys empirical work on this

the free trade epidemic of the 1860s and other outbreaks of economic discrimination why was there an abrupt increase in economic openness in europe in the 1860s this increase may have been the result of a contagion process in which the cobden chevalier treaty between britain and france threatened to displace third party exports to fra nce with british exports as a result most european states signed similar treaties with france which had further ripple effects this article outlines a formal model of this process based on the assumption that an agreement between two states incre ases the desirability of similar treaties to third parties propositions regarding the rate and pattern of spread of treaties are derived from this model this article then discusses the insights these propositions may offer into the rise and fall of the most favored nation network of treaties between 1860 and 1929 at a theoretical level the model aims to link the microlevel processes underlying state preferences to system level phenomena at a substantive level this analysis offers insight into the current explosion of regionalism

demand and distributional effects of water pricing policies abstract worldwide water scarcity threatens delivery of water to urban centers water pricing is often recommended to reduce demand in this paper demand and distributional effects of water pricing policies are examined in a block pricing model that is applied to the metropolitan region of sao paulo water demand functions are estimated using marginal and average price models based on monthly data for the period 1997 2002 price elasticities of water demand range between 0 45 and 0 50 and income elasticities between 0 39 and 0 42 for the current combined regressive progressive block price system the poor spend almost 4 2 to 4 7 of their income on water the rich only pay 0 4 to 0 5 of their income whereas they consume more than twice as much a progressive block price or an income dependent price system may result in a more equalized income distribution however the analysis shows that there is a trade off between a more equalized income distribution and revenues earned by the water company more pro poor pricing systems may result as well in lower revenues for the water company

stochastic cascades credit contagion and large portfolio losses abstract we analyze an interactive model of credit ratings where external shocks spread by a contagious chain reaction to the entire economy counterparty relationships along with discrete adjustments of credit ratings generate a transition mechanism that allows the financial distress of one firm to spill over to its business partners the spread of financial distress constitutes a source of intrinsic risk for large portfolios of credit sensitive securities that cannot be diversified away we provide a characterization of the fluctuations of credit ratings in large economies when adjustments follow a threshold rule and analyze the effects of downgrading cascades on credit portfolios

search unemployment and age abstract we examine a search and matching model of the labor market with overlapping generations of workers in this model we focus on the effects of the finite lifetime of workers as a result of finite lifetime very old workers with the same productivity as younger workers generally earn less a market solution with nash bargained wages is never optimal as old workers search too long compared to the efficient solution we also examine the effects of policy measures such as hiring subsidies or unemployment insurance on employment labor market institutions have a differential impact for different age groups

the effect of unemployment insurance on the riskiness of occupational choice abstract this paper examines the effect of unemployment insurance on the riskiness of occupational choice by postulating a model of job search in which job offers have two characteristics their wage and their security of tenure two versions are considered a general case in which the unemployment benefit is earnings related and a special case in which the benefit is of a flat rate form of particular interest in the paper is the individual s desired trade off between wage and security of tenure and how this trade off is affected by the type of insurance scheme in operation perhaps surprisingly we find that an earnings related scheme encourages risk taking behaviour by the poor and risk avoiding behaviour by the rich in contrast a flat rate scheme neither encourages nor discourages risk taking

the effect of ideological positions on job market interaction a spatial analysis abstract reporters and editors may not have the same ideology when an editor wants to employ a new reporter with a different ideology they have to negotiate the price of moving from their own ideology to the other s ideology we focus on the job market for reporters where the agents negotiate over the ideological position to be reported and wage we adopt a spatial model in which each agent suffers a utility loss as the agreed upon position moves away from his her favored one equilibrium determines a threshold ideological gap for a match to be formed our analysis generates a natural separation between extreme mildly extreme and moderate ideologies furthermore we find that agents that hold extreme ideologies compromise less than moderates this formulation may be applied to other situations in which agents involve monetary and non monetary considerations especially a preference for social proximity jel codes j32 j44

beyond gaussian averages redirecting international business and management research toward extreme events and power laws practicing managers live in a world of extremes but international business and management research is based on gaussian statistics that rule out such extremes on occasion positive feedback processes among interactive data points cause extreme events characterized by power laws they seem ubiquitous we list 80 kinds of them half each among natural and social phenomena we use imposed tension and per bak s self organized criticality to argue that pareto based science and statistics based on interdependence positive feedback scalability nearly infinite variance and emphasizing extremes should parallel the traditional dominance of gaussian statistics based on independent data points finite variance and emphasizing averages we question quantitative journal publications depending on gaussian statistics the cost is inaccurate science and irrelevance to practitioners in conclusion no statistical findings should be accepted into business studies if they gain significance via some assumption device by which extreme events and nearly infinite variance are ignored accordingly we suggest redirecting international business studies and management research in general

are output growth rate distributions fat tailed some evidence from oecd countries this work explores some distributional properties of aggregate output growth rate time series we show that in the majority of oecd countries output growth rate distributions are well approximated by symmetric exponential power densities with tails much fatter than those of a gaussian fat tails robustly emerge in output growth rates independently of i the way we measure aggregate output ii the family of densities employed in the estimation iii the length of time lags used to compute growth rates we also show that fat tails still characterize output growth rate distributions even after one washes away outliers autocorrelation and heteroscedasticity

aggregation and irrelevance in multi sector models abstract this paper studies the ability of input output relationships to generate fluctuations in aggregate output in several multi sector models including that of long and plosser 1983 in these models the manufacture of each sector s output depends on other sectors for materials these interconnections provide a mechanism for transmission of shocks across sectors and over time we ask how aggregates from these multi sector models behave relative to single sector models we provide conditions under which the second moment properties of aggregates in these models are the same as their single sector counterparts we further demonstrate that a broad class of input output structures generate aggregates with identical second moment properties and that the input output structures in this class provide a poor amplification mechanism for sector shocks

determinants of residential water demand in germany abstract we econometrically analyze the impact of several economic environmental and social determinants for the per capita demand for water in about 600 water supply areas in germany besides prices income and household size we consider the effects of population age the share of wells housing patterns precipitation and temperature we also explore why current per capita residential water consumption in the new federal states is about 30 lower than in the old federal states since average cost pricing may cause an endogeneity problem we apply instrumental variable procedures in addition to single equation ordinary least squares but find no evidence that prices are endogenous our estimation results suggest that the price elasticity of water demand in germany is around 0 24 the income elasticity is positive decreases with higher income levels and is at least three times higher in the new federal states than in the old federal states current differences in prices and income levels explain about one third of the gap in residential water use between the two regions household size and the share of wells have a negative impact on per capita water demand and water use increases with age finally the findings provide some evidence that rainfall patterns rather than total rainfall affect water consumption while temperature appears to have no impact at all all outcomes are robust to a log log and two types of semi log specifications for the water demand function

marriage markets and money a coasian theory of household formation this article integrates search based models of marriage and money we think about households as organizations the way coase thinks about firms as alternatives to markets that become more attractive when transactions costs increase in the model individuals consume market and home produced goods and home production is facilitated by marriage market frictions including taxes search and bargaining problems increase the marriage propensity the inflation tax encourages marriage because being single is cash intensive microdata confirm singles use cash more than married people we use macrodata over many countries to investigate how marriage responds to inflation taxation and other variables

is all domestic water consumption sensitive to price control this paper presents a model of residential water demand based on the stone geary utility function which explicitly considers a threshold of water that is insensitive to price and a quantity that can adapt instantaneously to price changes first the threshold is assumed constant being then allowed to vary according to past levels of consumption a proxy for households water using equipment and habits a measure of the depreciation rate of habits is derived and the effectiveness of price and non price conservation measures are compared the results provide useful policy recommendations for the studied case of seville spain

efficiency and equity in natural resources pricing a proposal for urban water distribution service this paper focuses on the design of optimal prices for urban water distribution service in this context pricing should be aimed at achieving efficiency equity financial aspects and or public acceptability and transparency the proposed tariffs are based on the theoretical frameworks suggested by ramsey 1927 and feldstein 1972 as a prior step estimations of urban water demands and water costs are carried out for the spanish municipality of seville finally an empirical comparison in welfare terms is conducted between the proposed tariffs and those applicable in the year 2000

estimating water demand under increasing block tariffs using aggregate data and proportions of users per block forming a strategy for the management of a water resource requires reasonable knowledge of the effects that alterations in the control variables bring on water use such knowledge of the determinants influencing domestic water demand constitutes an essential ingredient of a pricing policy for domestic water supply special attention should be paid to the effects of the level shape and frequency of the tariff since these are the variables that can be altered by the policy maker

self organized criticality in a dynamic game we investigate conditions under which self organized criticality soc arises in a version of a dynamic entry game in the simplest version of the game there is a single location a pool and one agent is exogenously dropped into the pool every period payoffs to entrants are positive as long as the number of agents in the pool is below a critical level if an agent chooses to exit he cannot re enter resulting in a future payoff of zero agents in the pool decide simultaneously each period whether to stay in or not we characterize the symmetric mixed strategy equilibrium of the resulting dynamic game we then introduce local interactions between agents that occupy neighboring pools and demonstrate that under our payoff structure local interaction effects are necessary and sufficient for soc and for an associated power law to emerge thus we provide an explicit game theoretic model of the mechanism through which soc can arise in a social context with forward looking agents

scaling the volatility of gdp growth rates abstract the distribution of shocks to gdp growth rates is found to be exponential rather than normal their standard deviation scales with gdp where 0 15 0 03 these macroeconomic results place restrictions on the microeconomic structure of interactions between agents

effect of price information on residential water demand microeconomic theory predicts that people decrease consumption when price increases the magnitude of the effect depending on price elasticity the law of demand however implicitly assumes that consumers know prices an assumption that is not always satisfied in markets with ex post billing when prices are not transparent elasticity estimates are potentially lower than their full information potential evidence of low price elasticity abounds in residential water demand studies limiting the effectiveness and desirability of using price signals as a conservation tool it is hypothesized that resident s sluggish response to price is partly due to the absence of price information on water bills differences in the informational content of bills are documented for the first time on the basis of sample bills collected from 383 utilities across the usa a standard aggregate water demand model is augmented with qualitative variables describing differences in billing information allowing such variables to a

a look into the nature of complex systems and beyond stonehenge economics coping with complexity or ignoring it in applied economics real world economic systems are complex in general but can be approximated by the open systems approach economic systems are very likely to possess the basic and advanced emergent properties e g self organized criticality fractals attractors of general complex systems t he theory of self organized criticality is proposed as a major source of dynamic equilibria and complexity in economic systems this is exemplified in an analysis for self organized criticality of danish agricultural subsectors indicated by power law distributions of the monetary production value for the time period from 1963 to 1999 major conclusions from the empirical part are 1 the sectors under investigation are obviously self organizing and thus very likely to show a range of complex properties 2 the characteristics of the power law distributions that were measured might contain further information about the state or graduation of self organization in the sector varying empirical results for different agricultural sectors turned out to be consistent with the theory of self organized criticality 3 fully self organizing sectors might be economically the most efficient finally empirical implications of the results are discussed complexity theory should be considered as a valuable supplement to the existing analytical toolbox jel classification b52

residential water demand in the northwest of spain a panel of monthly aggregate data from the northwest of spain is used to estimate domestic water demand functions under linear and non linear tariffs price billing climatic and sociodemographic variables are used as explanatory variables the use of intraannual data constitutes a relevant contribution in the european context overall marginal price elasticity estimates lie between 0 12 and 0 17 summer only elasticities and elasticities associated with uses beyond the effectively free allowances seem significantly higher climatic variables significantly affect monthly use although probably less than in other wealthier and drier areas domestic water use appears to be a normal good

cascading failures in production networks i show how the extensive margin of firm entry and exit can greatly amplify idiosyncratic shocks in an economy with a production network i show that canonical input output models which lack the extensive margin of firm entry and exit have some crucial limitations in these models the systemic importance of a firm does not respond to productivity shocks depends only on the firm s role as a supplier and is equal to or well approximated by the firm s size this means that for every canonical input output model there exists a non interconnected model that has the same aggregate response to productivity shocks i show that when we allow for entry and exit the systemic importance of a firm responds endogenously to productivity shocks depends on a firm s role not just as a supplier but also as a consumer and a firm s systemic influence is no longer well approximated by its size furthermore i show that nondivisibilities in systemically important industries can cause one failure to snowball into a large scale avalanche of failures in this sense shocks can be amplified as they travel through the network whereas in canonical input output models they cannot