Inventory Dynamics and Business Cycles: What Has Changed?

To what extent can information-technology led improvements in inventory management account for the apparent moderation of economic fluctuations in the United States since the mid-1980s? We argue that changes in inventory dynamics played a reinforcing—rather than a leading—role in the reduction of output volatility. Since the mid-1980s, inventory dynamics have changed in a manner consistent with a faster resolution of inventory imbalances. However, these changes appear to be a consequence of changes in the response of industry-level sales and aggregate economic activity to monetary policy shocks. Our results suggest that it is the interaction between the changes in inventory behavior at the industry level and the macroeconomic environment—where the latter likely includes changes in the conduct of monetary policy and the responses of the economy to policy disturbances—rather than any single factor, that has contributed importantly to the observed decline in economic volatility.     

Analyzing U.S. Output and the Great Moderation by Simultaneous Unobserved Components

This paper seeks to determine the causal interaction between structural trend and cycle innovations in an unobserved components framework of aggregate output. For the purpose of identification, I propose allowing for shifts in volatility. This strategy provides good estimation precision when applied to U.S. industrial production. In the early 1980s, predominance of cycle shocks gives way to strong negative spillovers of trend impulses, consistent with real business cycle theories. The coincident reduction of macroeconomic volatility was mainly caused by pronounced dampening of transitory disturbances. This is in accordance with an important role of macroeconomic policy in explaining the Great Moderation.     

The "Great Moderation" in the United Kingdom

We use a Bayesian time-varying parameters structural VAR with stochastic volatility for GDP deflator inflation, real GDP growth, a 3-month nominal rate, and the rate of growth of M4 to investigate the underlying causes of the Great Moderation in the United Kingdom. Our evidence points toward a dominant role played by good luck in fostering the more stable macroeconomic environment of the last two decades. Results from counterfactual simulations, in particular, show that (i) "bringing the Monetary Policy Committee back in time" would only have had a limited impact on the Great Inflation episode, at the cost of lower output growth; (ii) imposing the 1970s monetary rule over the entire sample period would have made almost no difference in terms of inflation and output growth outcomes; and (iii) the Great Inflation was due, to a dominant extent, to large demand non-policy shocks, and to a lesser extent—especially in 1973 and 1979—to supply shocks.     

The role of credit in the Great Moderation: A multivariate GARCH approach

During the Great Moderation, financial innovation in the US increased the size and scope of credit flows supporting the growth of wealth. We hypothesize that spending out of wealth came to finance a wider range of GDP components such that it smoothed GDP. Both these trends combined would be consistent with a decrease in the volatility of output. We suggest testable implications in terms of both growth of credit and output and volatility of growth. In a multivariate GARCH framework, we test this view for home mortgages and residential investment. We observe unidirectional causality in variance from total output, residential investment and non-residential output to mortgage lending before, but not during the Great Moderation. These findings are consistent with a role for credit dynamics in explaining the Great Moderation.     

Financial Frictions,Financial Shocks,and Aggregate Volatility

The Great Moderation was accompanied by an increase in financial volatility. We explore the sources of these divergent patterns in volatilities by estimating a model with time‐varying financial rigidities subject to structural breaks in the size of shocks, the monetary policy rule coefficients, and the average size of the financial rigidity. Institutional changes are key in accounting for the Great Moderation and in shaping the transmission mechanism of financial shocks. The increase in financial volatilities is accounted for by larger financial shocks, but the vulnerability of the economy to these shocks is significantly alleviated by the estimated changes in institutions.     

Understanding the inventory cycle

Careful examination of aggregate data from the U.S. and other OECD countries reveals that production and inventory behavior exhibit paradoxical features: (1) Inventory investment is strongly countercyclical at very high frequencies (e.g., 2-3 quarters per cycle); it is procyclical only at relatively low-cyclical frequencies such as the business-cycle frequencies (e.g., 8-40 quarters per cycle). (2) Production is less volatile than sales around the high frequencies; it is more volatile than sales only around business-cycle or lower frequencies. (3) Unlike capital investment or GDP, the bulk of the variance of inventory investment is concentrated around high frequencies rather than around business-cycle frequencies. These features of production and inventory behavior at the low and high frequencies provide a litmus test for inventory theories. This paper shows that the stockout-avoidance theory [Kahn, J., 1987. Inventories and the volatility of production. American Economic Review 77, 667-679.] has much better potential than other competing theories for explaining the seemingly paradoxical features of inventory fluctuations observed at different cyclical frequencies. My analysis suggests that demand shocks are the main source of the business cycle.     

Do Banks Affect the Level and Composition of Industrial Volatility?

In theory, better access to bank credit can reduce or increase output volatility depending on whether firms are more financially constrained during contractions or expansions. This paper finds that the volatility of industrial output is lower in countries with more bank credit. Most of the reduction in volatility is idiosyncratic, which follows from the ability of banks to pool and diversify shocks. Systematic volatility is reduced less strongly. Volatility dampening is achieved via countercyclical borrowing: At the firm level, short‐term borrowing is less (or more negatively) correlated with sales and inventories in countries with high levels of bank credit.     

Exchange rate volatility and the time-varying effects of aggregate shocks

This paper investigates the dynamics of the real exchange rate and relative output among the US and five of its top six trading partners since the collapse of Bretton Woods. It employs long-run restrictions to identify the usual suspect macroeconomic shocks and their relative importance for exchange rate fluctuations. An improvement of the econometric application is that it allows for the contribution of each shock to the real exchange rate and relative output to vary over time. While the volatility of US output – both total and relative to that of the UK or Canada – is estimated to have substantially reduced since the mid-1980s, consistent with the Great Moderation findings of many others, the volatility of real exchange rates has experienced a gradual and continuous increase over the same period. Monetary shocks account for only a small fraction of these dynamics, although they do track well the increase in volatility of US output during the Great Inflation period. It is supply-type shocks that seem to be more important for the relative output volatility reductions of the mid-1980s. Conversely, demand shocks seem to account for the largest portion of the volatility increases in the real exchange rate. Perhaps unsurprisingly, both volatilities increase during the 2007 financial crisis and the ensuing 2008–2009 Great Recession – periods associated with higher economic uncertainty.     

Economic volatility and financial markets: The case of mortgage‐backed securities

The volatility of aggregate economic activity in the United States decreased markedly in the mid‐eighties. The decrease involved several components of GDP and has been linked to a more stable economic environment, identified by smaller shocks, more effective policy, and a diverse set of innovations in technology as well as financial markets. We study one such financial innovation, and document a negative relation between the rapid growth of mortgage‐backed securities and the volatility of GDP and some of its components from the mid‐1970s to the late 1990s. We also document that this relation changed sign, from negative to positive, in the early 2000s.     

Cyclical Changes in Firm Volatility

We characterize trends and cycles in the volatility of U.S. firms using a measure that we argue more cleanly captures firm‐specific volatility in sales and earnings growth than standard measures do. While earlier literature has emphasized a trend increase in the volatility of publicly traded firms, we find that a typical publicly traded firm has become more stable. We find that the negative association between firm‐specific volatility and the business cycle is weaker than earlier research based on dispersion measures suggests. We find that during the Great Recession of 2007–2009, firm‐specific volatility increased moderately but never substantially exceeded its sample mean. Our results are inconsistent with the hypothesis that firm‐specific volatility is an important driver of the business cycle, as it theoretically could be through an effect of default risk on credit spreads.     

The Structural Dynamics of U.S. Output and Inflation: What Explains the Changes?

We examine the dynamics of U.S. output and inflation using a structural time-varying coefficients vector autoregression. There are changes in the volatility of both variables and in the persistence of inflation, but variations are statistically insignificant. Technology shocks explain changes in output volatility; real demand disturbances variations in the persistence and volatility of inflation. We detect important time variations in the transmission of technology shocks to output and demand shocks to inflation and significant changes in the variance of technology and of monetary policy shocks.     

Investment‐Specific News Shocks and U.S. Business Cycles

We provide robust evidence that news shocks about future investment‐specific technology (IST) constitute a significant force behind U.S. business cycles. Positive IST news shocks induce comovement, that is, raise output, consumption, investment, and hours. These shocks account for 70% of the business cycle variation in output, hours, and consumption, and 60% of the variation in investment, and have played an important role in 9 of the last 10 U.S. recessions. Our findings provide strong support for shifting focus to IST news shocks when investigating the role of news in driving U.S. business cycles.     

Monetary policy and aggregate volatility

Discretionary conduct of monetary stabilization policy can increase real and nominal aggregate volatility by arbitrary amounts when firms pay limited attention to aggregate shocks. A conservative central banker with stronger preference for price stability eliminates the commitment problem, thereby reduces output and price volatility and gives rise to a policy-induced ‘Great Moderation’. Increased focus on price stability facilitates firms’ information processing and aligns their expectations better with policy decisions. This ‘coordination effect’ reduces aggregate real and nominal volatility. Consistent with empirical evidence, the moderation manifests itself through reduced residual variance in vector autoregressions (VARs) involving macroeconomic variables.     

Inventories, employment and hours

This paper develops a model that integrates inventory and labor decisions. We extend a model of inventory behavior to include a detailed specification of the role of labor input in the production process, distinguishing between employment, hours and effort per worker. We estimate jointly the Euler equations for inventories and employment, a labor compensation schedule, and an hours requirement function with the cross-equation restrictions imposed. The econometric results shed light on several important topics, including the shape of the marginal cost of output, the role of labor hoarding as an explanation of pro-cyclical productivity, and the persistence of inventory stocks.     

Dynamic risksharing in the United States and Europe

We use a panel VAR model to improve upon the existing methodologies to analyze interregional risksharing and consumption smoothing channels. First, we endogenize the output process within a more general multi-equation framework, capturing the dynamic feedback between output and various smoothing channels. Second, in line with dynamic general equilibrium open economy models of risksharing, we exploit impulse response functions to trace the role of each smoothing channel over time, in the presence of different structural shocks (temporary vs. permanent and output vs. smoothing channels). In the application to the US and OECD countries, we find different dynamic properties of different smoothing channels. We compare our results with the predictions of standard risksharing and consumption theories, and tackle some of the puzzles in the literature, such as the “international risksharing puzzle” and the “consumption-output correlation puzzle.” We are also able to address such policy issues as whether fiscal stabilizers have been substitutes or complements for financial market diversification activities and whether further financial market integration is likely to provide countries with more shock-absorption tools. A key result is the strong substitutability between capital and credit smoothing in the US, and between fiscal and credit smoothing in the OECD.     

Evaluating the Macroeconomic Effects of the ECB's Unconventional Monetary Policies

We quantify the macroeconomic effects of the European Central Bank's unconventional monetary policies using a dynamic stochastic general equilibrium model which includes a set of shadow interest rates. Extracted from the yield curve, these shadow rates provide unconstrained measures of the overall stance of monetary policy. Counterfactual analyses show that, without unconventional measures, the euro area would have suffered (i) a substantial loss of output since the Great Recession and (ii) a period of deflation from mid‐2015 to early 2017. Specifically, year‐on‐year inflation and GDP growth would have been on average about 0.61% and 1.09% below their actual levels over the period 2014Q1–17Q2, respectively.     

The Real‐Time Properties of the Bank of Canada's Staff Output Gap Estimates

We study the revision properties of the Bank of Canada's staff output gap estimates since the mid‐1980s and show that the average revision has been significantly smaller since the early 2000s. Alternatively, revisions from econometric output gap estimates have not experienced a similar improvement. We show that the overestimation of potential output in real time following the 1991–92 recession explains the large revisions in the first half of the sample. Although Phillips‐curve inflation forecasts slightly worsen when conditioned on real time instead of final gaps, their relative poor performance reflects the general lack of inflation predictability rather than real‐time gap measurement issues.     

How much should inflation targeters care about the exchange rate?

A DSGE model is used to examine whether including the exchange rate in the central bank’s policy rule can improve economic performance. Smoothing the exchange rate helps both financially-robust economies and financially-vulnerable emerging economies in handling risk premium shocks and, given a small weight placed on the exchange rate, the effects on inflation and output volatility are minimal with demand and cost-push shocks. Financially-vulnerable economies are especially likely to benefit from exchange rate smoothing due to perverse movements of the exchange rate they experience when hit by demand shocks and being more prone to risk premium shocks.     

The Role of Oil Price Shocks in Causing U.S. Recessions

Although oil price shocks have long been viewed as one of the leading candidates for explaining U.S. recessions, surprisingly little is known about the extent to which oil price shocks explain recessions. We provide a formal analysis of this question with special attention to the possible role of net oil price increases in amplifying the transmission of oil price shocks. We quantify the conditional effect of oil price shocks in the net oil price increase model for all episodes of net oil price increases since the mid‐1970s, analyze its determinants, and show that the linear model fits the data better.     

Business cycles in emerging economies: the role of interest rates

We find that in a sample of emerging economies business cycles are more volatile than in developed ones, real interest rates are countercyclical and lead the cycle, consumption is more volatile than output and net exports are strongly countercyclical. We present a model of a small open economy, where the real interest rate is decomposed in an international rate and a country risk component. Country risk is affected by fundamental shocks but, through the presence of working capital, also amplifies the effects of those shocks. The model generates business cycles consistent with Argentine data. Eliminating country risk lowers Argentine output volatility by 27% while stabilizing international rates lowers it by less than 3%.