explaining business cycles in small open economies abstract this paper analyzes the role of world price shocks fluctuations in the prices of capital intermediate and primary goods and in the world real interest rate in the generation and propagation of business cycles in small open developing countries i construct a stochastic dynamic multi sector small open economy model the model is a variant of the specific factors model and reflects the major structural characteristics of developing economies i utilize variance decomposition methods to quantitatively evaluate the impact of world price shocks the results indicate that world price shocks account for a significant fraction of business cycle variability in developing countries

agricultural price instability a survey of competing explanations and remedies there are two explanations for agricultural price dynamics one follows cobweb logic and models fluctuations driven by expectation errors but emphasises that these expectations create complex dynamics and possibly chaos the other stems from the rational expectations tradition of dynamics driven by real shocks the empirical evidence tends to support the latter but is not conclusive the rational expectations model generates an optimal dynamic path from which no improvement can be expected from public intervention however if we take account of all the potential market failures in agricultural markets and especially in developing countries this conclusion might require some qualifications although an appropriate policy design for stability has still to be achieved this paper surveys the positive and normative literature on agricultural prices highlighting empirical evidence and identifying remaining unresolved issues

does economic structure determine financial structure abstract in this paper we examine the relationship between the structure of the real economy and a country s financial system we consider whether the development of the real economic structure can predict the direction of evolution of a country s financial structure using data for 108 countries we find a significant relationship between real economic structure and financial structure next we exploit shocks to the economies in india finland and sweden and south korea and show that changes in the economic structure of a country influence the evolution of its financial system this suggests that financial institutions and capital markets change in response to the structure of industries

business cycle theory and econometrics we outline in turn criticisms made by econometricians of the methods used in empirical business cycle research and then criticisms made by business cycle researchers of some methods used by econometricians the aim is to clarify and in some cases correct thesecriticisms overall there is no conflict in using rigourous statistical procedures to study modern dynamic stochastic general equilibrium models we also provide a concise bibliographyof recent research on statistical methods for business cycle models

technology shocks technological collaboration and innovation outcomes in the early to mid 1990s technology alliances suddenly surged to unprecedented levels roughly 300 growth per year from 1990 to 1995 and then declined just as precipitously this massive increase in alliance activity caused the crystallization of a giant component in the global technology network that connected a large portion of the world s firms government labs universities and other organizations however when alliance activity declined the component disintegrated what caused this spike in alliance activity and did this large but transient change in collaboration activity leave any enduring effect the data here suggest that a major technology shock may have provoked this alliance surge a technology shock may simultaneously unleash significant innovation opportunities while creating great uncertainty in the economic environment though it is well known that firms often use alliances both to respond to uncertainty and facilitate innovation little is known about how technology shocks affect the collaboration behavior of firms and how these two factors separately influence innovation outcomes i integrate an inductive study of collaboration activity and a technology shock with existing research on economics alliances and networks to build a set of arguments about how technology shocks will influence alliance behavior how changes in alliance behavior will influence the global technology collaboration network and about how each of these changes is likely to influence the innovative outcomes of firms i then explore the separate and joint effects of the technology shock and collaboration activity on innovation using a large sample panel study of patenting by north american firms

an equilibrium theory of nominal and real exchange rate comovement abstract this study develops a quantitative equilibrium theory to offer an explanation of one of the most puzzling aspects of empirical exchange rate behavior the high degree of nominal and real exchange rate comovement technology shocks coupled with the accomodative response of monetary policy to output fluctuations are primarily responsible for the covariation between nominal and real exchange rates shocks to the marginal efficiency of investment also play an important role

computable general equilibrium models and monetary policy advice this paper argues that variations of extant general equilibrium monetary models are capable of generating real time economic forecasts comparable in accuracy to those generated under the standard federal reserve board staff methodology specifically we argue that over the 1984 1990 period forecasts generated by versions of the limited participation models developed by fuerst 1992 and christian0 and eichenbaum 1992a 1992b compare favorably with those contained in the board staff s greenbook briefing documents we conclude that further development of these models holds promise for fully integrating the forecasting and policy analysis elements of the federal reserve s monetary policy advice process

a definition of more systematic risk with some welfare implications producers are subject to similar production risks and so their outputs are likely correlated using the entire data set rather than summary statistics we study an ordinal definition of systematic risk for risk neutral producers in perfect competition we trace the effects of an increase in systematic risk through to impacts on welfare measures and production decisions expected welfare falls under more systematic risk but either of expected producer surplus or expected consumer surplus may rise our definition of systematic risk also has relevance for the incentive to incur r d expenditures the benefits of diversity and the gains from risksharing

factor demand linkages technology shocks and the business cycle abstract this paper argues that factor demand linkages can be important for the transmission of both sectoral and aggregate shocks we show this using a panel of highly disaggregated manufacturing sectors together with sectoral structural vars when sectoral interactions are explicitly accounted for a contemporaneous technology shock to all manufacturing sectors implies a positive response in both output and hours at the aggregate level otherwise there is a negative correlation as in much of the existing literature furthermore we find that technology shocks are important drivers of the business cycle

grain price stabilization in india evaluation of policy alternatives abstract stabilization of prices is an important element of food policy in india as in most other countries both developing and developed however since the magnitude of grain stocks held for this purpose as well as the costs of physical storage have become prohibitively high there is now a need for finding cost effective alternatives including non interventionist and market oriented methods for price stabilization in this paper we consider the case of rice and wheat which are staple foodgrains in india we make a comparison between alternative price stabilization policies including that of holding buffer stocks in terms of their impact on domestic price stability producer and consumer welfare and government costs a multi market equilibrium framework is used where private storage consumption supply and prices of rice and wheat are determined simultaneously indian exports and imports are assumed to affect world prices the alternative price stabilizing mechanisms are ranked according to both the criteria welfare and price stability achieved the main findings are as follows the ranking of alternatives varies with the criterion used greater price stability need not necessarily imply greater welfare the option of variable levies on private external trade turns out to be the most inexpensive and that of domestic buffer stocks the costliest in achieving price stability further the efficacy of buffer stocks and subsidy to private storage in stabilizing prices is lower under free trade as compared to the case where the economy is closed to private external trade

what happens during recessions crunches and busts we provide a comprehensive empirical characterization of the linkages between key macroeconomic and financial variables around business and financial cycles for 21 oecd countries over the period 1960 2007 in particular we analyse the implications of 122 recessions 113 28 credit contraction crunch episodes 114 28 episodes of house price declines busts 245 61 episodes of equity price declines busts and their various overlaps in these countries over the sample period our results indicate that the interactions between macroeconomic and financial variables can play a major role in determining the severity and duration of a recession specifically we find evidence that recessions associated with credit crunches and house price busts tend to be deeper and longer than other recessions stijn claessens m ayhan kose and marco e terrones

james tobin an appreciation of his contribution to economics jim tobin who died on march 11 2002 at the age of 84 was one of giants of economics of the second half of the twentieth century and the greatest macroeconomist of his generation tobin s influence on macroeconomic theory is so pervasive so much part of our professional acquis that many younger economists often are not even aware that it is his ideas they are elaborating testing criticising refuting or re inventing in this appreciation i consider tobin s scholarly contributions made over a period of more than 50 years tobin received the 1981 nobel memorial prize for his analysis of financial markets and their relations to expenditure decisions employment production and prices i consider his contributions to mean variance portfolio demand and asset pricing theory especially the portfolio separation theorem pitfalls in financial model building portfolio balance and flow of funds models and the credit channel the life cycle model and social security econometric methodology including the tobit estimator and his pioneering work using both time series and cross sectional data to estimate food demand functions economic growth tobin s q the tobin tax the monetary and fiscal policy effectiveness debate first with milton friedman and then with the new classical macroeconomics and real business cycle schools and tobin s approach to methodological questions including microfoundations and aggregation

how much of commodity price behavior can a rational expectations storage model explain a rational expectations competitive storage model was applied to the u s corn market to assess the aptness of this framework in explaining monthly price behavior in an actual commodity market relative to previous models extensive realism was added to the model in terms of how production activities and storage costs are specified by modeling convenience yield backwardation in prices between crop years did not depend on the unrealistic assumption of zero ending stocks our model generated cash prices that were distributed with positive skewness and kurtosis and mean and variance that increased over the storage season comparable to the persistence and the occasional spikes observed in commodity prices futures prices were generated as conditional expectations of cash prices at contract maturity and the variances of futures prices exhibited realistic time to maturity and seasonal patterns model realizations of cash and futures prices over many years were used to demonstrate the wide variety of price behaviors that could be observed in an efficient market with a similar market structure implying that economic and policy implications drawn from short historical samples of prices could be misleading

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

rising food prices food price volatility and social unrest can food prices cause social unrest throughout history riots have frequently broken out ostensibly as a consequence of high food prices using monthly data at the international level this article studies the impact of food prices food price levels as well as food price volatility on social unrest because food prices and social unrest are jointly determined data on natural disasters are used to identify the causal relationship flowing from food price levels to social unrest results indicate that for the period 1990 2011 food price increases have led to increases in social unrest whereas food price volatility has not been associated with increases in social unrest these results are robust to alternative definitions of social unrest to using real or nominal prices to using commodity specific price indices instead of aggregated price indices to alternative definitions of the instrumental variable to alternative definitions of volatility and to controlling for non food related social unrest

the optimal monetary response to technology shocks i introduction during the past decade many economists adopted the view that shocks to the aggregate production function or technology shocks represent the dominant source of fluctuations in the united states economy as noted by shapiro 1987 a number of elements came together to shape this view most important a series of severe supply shocks hit the economy during the 1970s standard keynesian models with their emphasis on the demand side had great difficulty tracking the economy s response to these shocks the view solidified after kydland and prescott 1982 demonstrated that many features of the business cycle can be replicated in a model where technology shocks are the only source of fluctuations kydland and prescott s work launched the now extensive literature on real business cycles surveyed by mccallum 1989 the observation that supply side disturbances are important in generating business cycles however need not imply that monetary factors play no role in accounting for variations in economic activity greenwood and huffman 1987 and cooley and hansen 1989 add cash in advance constraints to otherwise standard real business cycle models as a simple way of including the nominal sector in these cash in advance models monetary shocks have little effect on the cyclical behavior of real variables these models preserve the emphasis on technology shocks in explaining the business cycle nevertheless the models show how sustained inflation can affect the real economy by acting as a distortionary tax on productive activity the models of greenwood and huffman and cooley and hansen imply that optimal monetary policy involves a steady contraction of the money supply that keeps the nominal interest rate at zero as called for by friedman 1969 this optimal policy makes no attempt to respond to technology shocks instead it simply removes the distortionary inflation tax more recently cho and cooley 1992 yun 1994a and dow 1995 have investigated the effects of introducing various forms of price rigidity into monetary versions of the real business cycle model technology shocks continue to play a major role in these studies but the presence of nominal rigidities allows monetary shocks to affect the business cycle as well in fact these studies show that the addition of price rigidity improves the model s ability to match the cyclical properties of the data this paper complements these studies by deriving the implications of nominal price rigidity for optimal monetary policy i begin by outlining a model that shares the basic features of those cited above including technology shocks a cash in advance constraint and nominal price rigidity in the model both technology and monetary shocks have important effects on aggregate output and employment unlike flexible price cash in advance models for instance the model developed here gives rise to a phillips curve relationship between money and output the model is used to answer the following question does the presence of nominal price rigidity rationalize a monetary policy that responds actively to technology shocks or does the optimality of friedman s constant money growth rule still apply the results show that optimal policy does in fact exploit the monetary authority s ability to influence the real economy when prices are sticky that is the optimal policy is activist on the other hand the results also show that the friedman rule while no longer optimal comes very close to the optimum in welfare terms in this sense the main policy implication of flexible price cash in advance models appears robust to the introduction of nominal price rigidity section ii presents the model section iii describes the key features of its equilibrium section iv derives the optimal activist policy and compares its performance to that of the friedman rule section v concludes ii the model the economic environment infinitely lived households firms and a monetary authority populate an economy where time periods are indexed by t 0 1 2

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

supplanting the minnesota prior forecasting macroeconomic time series using real business cycle model priors abstract although general equilibrium models are in wide use in the theoretical macroeconomic literature their empirical relevance is uncertain we develop procedures for using dynamic general equilibrium models to aid in analyzing the observed time series relationships among macroeconomic variables our strategy is based on that developed by doan litterman and sims 1984 who constructed a procedure for improving time series forecasts by shrinking vector autoregression coefficient estimates toward a prior view that vector time series are well described as collections of independent random walks in our case the prior is derived from a fully specified general equilibrium model we demonstrate that like the atheoretical random walk priors real business cycle model priors can aid in forecasting

optimal food price stabilization in a small open developing country in poor countries most governments implement policies aiming to stabilize the prices of staple foods which often include storage and trade measures insulating their domestic market from the world market it is of crucial importance to understand the precise motivations and efficiency of those interventions because they can have consequences worldwide this paper addresses those issues by analyzing the case of a small open developing country confronted by shocks to both the crop yield and foreign price in this model government interventions may be justified by the lack of an insurance market for food prices considering this market imperfection the authors design optimal public interventions through trade and storage policies they show that an optimal trade policy largely consists of subsidizing imports and taxing exports which benefits consumers at the expense of producers import subsidies alleviate the non negativity of food storage in other words when stocks are exhausted subsidizing imports prevents domestic price spikes one striking result an optimal storage policy on its own is detrimental to consumers since its stabilizing benefits leak into the world market and it raises the average domestic price by contrast an optimal combination of storage and trade policies results in a powerful stabilizing effect for domestic food prices

the role of preference shocks and capital utilization in the great depression the article examines the proposition that preference shocks play a central role in our understanding of the great depression i identify a series of unusually large negative shocks that destabilized the u s economy during the 1930s when the artificial economy is paired with variable capital utilization and mildly increasing returns to scale in production it is able to account for most of the decline in economic activity and it predicts a tepid recovery

the limits of business cycle research assessing the real business cycle model the real business cycle model dominates business cycle research in the new classical tradition typically real business cycle modelers both offer the bold conjecture that business cycles are equilibrium phenomena driven by technology shocks and also novel strategies for assessing the success of the model this article critically examines the real business model and the assessment strategy surveys the literature supporting and opposing the model and evaluates the evidence on the empirical success of the model it argues that on the preponderance of the evidence the real business cycle model is refuted copyright 1997 by oxford university press

gross credit flows the paper estimates gross credit flows for the u s banking system between 1979 and 1999 and shows that sizable gross flows coexist at any phase of the cycle even within narrowly defined loan categories bank size categories and regional units to investigate the macroeconomic dimensions of gross credit flows the paper studies the cyclical behavior of aggregate credit flows and documents three key cyclical facts first excess credit reallocation is countercyclical for any given rate of change of net credit gross flows are larger in a recession than in a boom second gross credit flows are highly volatile with a cyclical volatility which appears more than an order of magnitude larger than gdp volatility third credit contraction is more volatile than credit expansion furthermore the behavior of gross flows over the 1991 recession suggests that persistent and historically high credit contraction is a key feature of the relatively mild cyclical downturn the results lends some support to aggregate models that emphasize the asymmetric behavior of credit expansion and credit contractions

did technology shocks cause the 1990 91 recession real business cycle theory has been used to determine the statistical properties of aggregate fluctuations induced by technology shocks the finding is that technology shocks have been an important contributor to fluctuations in the u s economy for example finn e kydland and prescott 1991 estimate that if the only impulses were technology shocks the u s economy would have been 70 percent as volatile as it has been over the postwar period in this paper we employ the theory to answer the question did technology shocks cause the 1990 1991 recession answering this question requires the determination of the effects of technology shocks on the path of the economy the procedure that we use to make this determination is as follows first we construct a model economy and calibrate it so that its steady state matches actual 1987 values data for other years are used to determine the realizations of the shocks and the nature of the stochastic processes generating these shocks given these stochastic processes the equilibrium decision rules for our calibrated economy are computed we then construct the path for the economy implied by the model for the period 1984 1 1992 3 we set 1984 1 model values of the state variables equal to actual 1984 1 values and use the decision rules and the realized shocks to construct this path finally we examine whether the model economy experiences a recession in 1991 as did the u s economy business cycles are variations in output per adult that are in large part accounted for by variation in the per adult time allocated to market production figure 1 plots the time path of the per adult labor input during the 1983 1 1989 1 period there was a remarkable 12 percent increase in the labor input per adult beginning in 1990 2 there has been a decline of nearly 6 percent in this per adult labor input an unusual feature of the recovery subsequent to the 1990 1991 recession is that this labor input variable has continued to decline well into the recovery this unusual behavior leads to a related question did technology shocks cause the slow recovery we found it necessary to modify the standard real business cycle model in four ways in order to answer the posed question first given the enormous changes in the relative prices of durables as depicted in figure 2 we could not treat technology change as being neutral with respect to different types of final goods following john b long and charles plosser 1983 and jeremy greenwood et al 1992 we consider multiple production sectors with technology change differing across sectors second we assume that there is a technology employed within the household sector that produces a consumption flow from the stock of consumer durables third we consider land to be a factor of production in addition to labor and capital our fourth modification is to introduce population growth

the inefficiency of interest rate subsidies in commodity price stabilization interest rate subsidies have been used to stimulate commodity stockholding with the intention of stabilizing prices however reductions in price variability can be achieved at less government cost using a direct storage subsidy and it is possible that an interest rate subsidy will increase price variability even though the interest subsidy increases mean stocks held these results are demonstrated using a stochastic dynamic programming model of optimal private storage with parameter values relevant to agricultural commodity markets and with particular reference to the u s soybean market

the consequences of the us doj s antitrust activities a macroeconomic perspective do the antitrust law enforcement activities of the us department of justice act as exogenous technology shocks or as markup shocks limiting market power and promoting economic growth we analyze annual time series data from 1947 to 2003 on three measures of federal antitrust intervention the ratio of the antitrust division s budgetary expenditures to gdp as well as the numbers of civil and criminal antitrust cases instituted we find that changes in the levels of these policy variables act like negative technology shocks and that the negative effects are transitory antitrust policy generates no subsequent offsetting increases in productivity

the aggregate effects of sectoral reallocations abstract can a one time permanent change in the fundamentals behind the sectoral composition of the economy prompt an aggregate downturn can this downturn be non negligible even if one uses us data to determine the relative size of gross vs net job flows and the importance of job creation costs can one consider the military build down of the 1990s as a plausible cause for the 1990 1991 recession do sectoral reallocations generate responses that are qualitatively similar to productivity shocks we use a variant of the mortensen pissarides 1994 review of economic studies 61 397 415 job creation destruction model calibrate it to us labor market data and run experiments that suggest one can answer yes to all these questions

keynesian impulses versus solow residuals identifying sources of business cycle fluctuations we employ a neoclassical business cycle model that builds on the greenwood hercowitz and huffman 1988 variable utilization framework to study two sources of business cycl e fluctuations marginal efficiency of investment shocks and total factor productivity shocks the parameters of the model are estimated using a bayesian procedure that accommodates prior uncertainty about their magnitudes from these estimates posterior distributions of the two shocks are obtained the postwar u s experience suggests that both shocks are important in understanding fluctuations but that total factor productivity shocks are primarily responsible for beginning and ending recessions

income taxes and price variability in storable commodity markets progressive income taxes lead to distortions in economic decisions made across tax years this is particularly important when income is volatile as in the case of agriculture progressive taxes therefore can fundamentally change economic behavior over time this study explores how progressive income taxes influence storage decisions and the markets for storable commodities under a progressive tax system commodity storage tends to be lower in the aggregate and as a consequence price volatility increases these distortions could be eliminated by introducing a flat rate tax or by changing the tax reporting system for farmers

time to implement and aggregate fluctuations in this paper we slightly modify the canonical rbc model by adding an implementation lag in the technology to reproduce the fact that consumption is a leading indicator of output indeed we assume that agents have today some information on the realization of the technology shock that will occur tomorrow today inventions are known and give information on the innovations which will be implemented tomorrow the model is estimated and tested on us data by a simulated method of moments using some suitable reconstructed data that are compatible with that model the results are in favor of this implementation lag hypothesis the model is not rejected by us post war data

processing industry capacity and the welfare effects of sugar policies normally analysis of policies affecting commodities such as sugar employs long run comparative statics under certainty and ignores processing industries like cane sugar refining under the implicit assumption that the capital is malleable in both the short and long run we present a dynamic model calibrated to world sugar and solved with numerical dynamic programming that includes the specific capital of the refining industry when compared to an otherwise identical static model the dynamic model suggests that some 20 of welfare losses may be misattributed to cane sugar producers instead of refiners in contrast the difference between certainty and uncertainty proves to be unimportant

rules versus discretion in food storage policies this article compares various policies in a rational expectations food storage model with risk averse consumers and missing insurance markets calibrated to represent a developing country i consider an optimal storage policy under discretion and two optimal simple rules a constant private storage subsidy and a price band the storage subsidy achieves welfare gains similar to the discretionary policy the price band maximizing social welfare is a price peg scheme the floor and ceiling prices are the same and the capacity constraint represents 11 of the steady state production level this price band achieves three quarters of the gains from the optimal policy under discretion

the effects of direct storage subsidies under limited rationality a general equilibrium analysis we study here the effects of a public subsidy to private storage set up at world level to simulate the welfare effects and impacts on market fluctuations of this subsidy we use a dynamic computable general equilibrium model assuming imperfect expectations we also perform different statistical analysis based on our cge results and show that the storage subsidy can have the undesired effect of destabilizing agricultural markets depending on the form of economic agents price expectations and on the structure of the shocks impacting the agricultural production

evaluating the effectiveness of inter regional trade and storage in malawi s private sector maize markets abstract this paper evaluates the effectiveness of the private sector maize marketing system in malawi using threshold autoregression models two dimensions of maize market performance are evaluated 1 inter regional trade and spatial price transmission and 2 storage and seasonal price relationships in both cases threshold autoregression models which account for nonlinearities predicted by economic theory are applied results indicate that spatial price transmission and seasonal price patterns in private sector maize markets in malawi are generally consistent with long run competitive inter regional trade and storage behavior and that in most cases shocks to long run equilibrium are arbitraged away quickly this suggests the private sector in malawi is generally doing a good job of transporting maize from surplus to deficit regions and smoothing maize consumption between harvests

using theory for measurement an analysis of the cyclical behavior of home production abstract a significant amount of economic activity takes place within the home unfortunately it is difficult to assess the cyclical properties of home production because the available data are too sporadic using a real business cycle rbc model we construct quarterly data on three variables that are unobservable at a quarterly frequency hours worked in the home sector hours spent in leisure and the consumption of home produced goods three results emerge leisure is countercyclical while nonmarket hours are acyclical hours spent in home production have declined significantly since the 1970s fluctuations in market output are a good measure of fluctuations in individual utility as long as home and market consumption are either extreme complements or extreme substitutes in the production of utility

optimal food price stabilisation policy this paper proposes a framework for designing optimal food price stabilisation policies in a self sufficient developing country it uses a rational expectations storage model with risk averse consumers and incomplete markets government stabilises food prices by carrying public stock and by applying a state contingent subsidy tax to production the policy rules are designed to maximise intertemporal welfare the optimal policy under commitment crowds out all private stockholding activity by removing the profit opportunity from speculation the countercyclical subsidy tax to production helps price stabilisation by subsidising production in periods of scarcity and by taxing it in periods of glut it contributes little to welfare gains most of which come from stabilisation achieved through public storage

real business cycles in this paper we demonstrate how certain very ordinary economic principles lead maximizing individuals to choose consumption production plans that display many of the characteristics commonly associated with business cycles our explanation is entirely consistent with i rational expectations ii complete current information iii stable preferences iv no technological change v no long lived commodities vi no frictions or adjustment costs vii no government viii no money and ix no serial dependence in the stochastic elements of the environment we also provide a completely worked out example of the type of artificial economy we have in mind the time series properties of the example exhibit some major features of observed business cycles although this type of model may not be capable of explaining all of the regularities in actual business cycles we believe that it provides a useful well defined benchmark for assessing the relative importance of factors e g monetary disturbances

uncertainty irreversibility durable consumption and the great depression what was the role of uncertainty in the great depression this paper uses a calibrated general equilibrium model to show that in response to an increase in uncertainty agents increase expenditure on irreversible durable goods and reduce investment in irreversible physical capital these relative movements occur because durable goods provide a store of utility and are less irreversible than physical capital these substitutions are unclear at the start of the great depression but are clearly visible at the deep end of it in 1932 when the volatility of stock returns is consistently high coefficients on the variance which is consistent with the uncertainty hypothesis both the theoretical hypothesis and its empirical tests are of a partial equilibrium nature yet the great depression was a general equilibrium event this paper puts the uncertainty argument explicitly in a general equilibrium model with consumer durables and capital goods both subject to irreversibility constraints i associate income uncertainty with the stochastic process driving output fluctuations and an increase in uncertainty is modelled as a mean preserving spread on the distribution of this shock the general equilibrium setup also incorporates a specific notion of irreversibility namely that goods are irreversible if there are no buyers when one wants to sell the test of the uncertainty hypothesis in general equilibrium is a simulation of a calibrated version of the model what makes the reaction to a mean preserving spread nontrivial is the clash of the theoretical predictions of precautionary savings and irreversible investment in a general equilibrium context savings should increase and investment should fall to complicate matters durable goods have components of both consumption and investment so what was the role of uncertainty in the great depression in this setup a calibrated model provides a simple answer higher uncertainty makes agents cut capital investment and increase expenditure on durables there are two reasons for this the first is that durables are the least irreversible of the two assets in the model and the second is that durable goods act as a store of utility and thus as insurance the view of the uncertainty hypothesis that a cut in expenditure on durable goods is a key response to high uncertainty is not supported by a standard general equilibrium model there may however be some truth in itfbut for the wrong reasons and at the wrong time it is not a fall in durable expenditure per se but rather an increase relative to

semi parametric predictions of the intertemporal approach to the current account abstract this paper uses the method dynamic programming dp by gmm and canadian data to estimate a dynamic model of a small open economy dp by gmm has several appealing features it does not impose certainty equivalence it accommodates multiple shocks and imposes few restrictions on the properties of the shocks in the model also since it uses the actual shocks series to estimate approximate decision rules it produces sample paths for the endogenous variables in the model the model estimated fits the data well in particular the variance of the predicted trade balance output ratio matches its empirical counterpart