Karl Whelan

Has Euro-area Inflation Persistence Changed Over Time?

This paper analyzes the stability over time of the econometric process for euro-area inflation since 1970, focusing in particular on the behavior of the so-called persistence parameter (the sum of the coefficients on the lagged dependent variables). Perhaps surprisingly, in light of the Lucas critique, our principal finding is that there appears to be relatively little instability in the parameters of the euro-area inflation process. Full-sample estimates of the persistence parameter are generally close to 1, and we fail to reject the hypothesis that this parameter has been stable over time. We discuss how these results provide some indirect evidence against rational expectations models with strong forward-looking elements, such as the New Keynesian Phillips curve.

Computers, Obsolescence, And Productivity

This paper examines the role that computers have played in boosting U.S. economic growth in recent years. The paper focuses on two effects - the effect of increased productivity in the computer-producing sector and the effect of investments in computing equipment on the productivity of those who use them - and concludes that together they account for almost all of the recent acceleration in U.S. labor productivity. In calculating the computer-usage effect, standard NIPA measures of the capital stock are inappropriate for growth accounting because they do not account for technological obsolescence; this occurs when a machine that is still productive is retired because it is no longer near the technological frontier. Using a theoretical framework that explicitly accounts for technological obsolescence, alternative estimates of the computer capital stock are developed that imply larger effects on growth of computer capital accumulation than are suggested by the NIPA stocks.

Can Rational Expectations Sticky-Price Models Explain Inflation Dynamics

Recent years have seen an important trend in macroeconomic research towards analysing business cycles and stabilization policy in the context of models that incorporate both nominal rigidities and optimising agents with rational expectations. The canonical specification for the behaviour of inflation in these sticky-price rational expectations models (which is known as the new-Keynesian Phillips curve) is often criticized on the grounds that it fails to account for the dependence of inflation on its own lags. In response, many recent studies have employed a “hybrid” sticky-price specification in which inflation depends on a weighted average of lagged and expected future values of itself, in addition to a driving variable such as the output gap. In this paper, we consider some simple tests of the hybrid model that are derived from the models closed-form solution. Our results suggest that the hybrid model provides a poor description of empirical inflation dynamics, and that there is little evidence of the type of rational forward-looking behavior implied by the model.

Explaining the Investment Boom of the 1990s

Real equipment investment in the United States has boomed in recent years, led by soaring investment in computers. We find that traditional aggregate econometric models completely fail to capture the magnitude of this recent growth - mainly because these models neglect to address two features that are crucial (and unique) to the current investment boom. First, the pace at which firms replace depreciated capital has increased. Second, investment has been more sensitive to the cost of capital. We document that these two features stem from the special behavior of investment in computers and therefore propose a disaggregated approach. This produces an econometric model that successfully explains the 1990s equipment investment boom.

Does Labor's Share Drive Inflation?

A number of researchers have recently argued that the new-Keynesian Phillips curve matches the empirical behavior of inflation well when the labor income share is used as a driving variable, but fits poorly when deterministically detrended output is used. The theoretical motivation for these results rests on the idea that the output gap—the deviation between actual and potential output—is better captured by the labor income share, in turn implying that central banks should raise interest rates in response to increases in this variable. We show that the empirical evidence generally suggests that the labor share version of the new-Keynesian Phillips curve is a very poor model of price inflation. We conclude that there is little reason to view the labor income share as a good measure of the output gap, or as an appropriate variable for incorporation in a monetary policy rule.

On the Relationships between Real Consumption, Income, and Wealth

The existence of durable goods implies that the welfare flow from consumption cannot be directly associated with total consumption expenditures. As a result, tests of standard theories of consumption (such as the Permanent Income Hypothesis, or PIH) typically focus on nondurable goods and services. Specifically, these studies generally relate real consumption of nondurable goods and services to measures of real income and wealth, where the latter are deflated by a price index for total consumption expenditures. This paper demonstrates that this procedure is only valid under the assumption that real consumption of nondurables and services is a constant multiple of aggregate real consumption outlays - an assumption that represents a very poor description of U.S. data. The paper develops an alternative approach that is based on the observation that the ratio of these series has historically been stable in nominal terms, and uses this approach to examine two basic predictions of the PIH. We obtain significantly different results relative to the traditional approach.

The Irish expansionary fiscal contraction: A tale from one small European economy

Abstract Irish experience during a recent period of severe fiscal adjustment attracted international attention and was claimed to demonstrate an expansionary fiscal contraction. Using a small structural model which fits the stylized facts, we question the extent to which analysis provides convincing evidence in favour of the EFC hypothesis. Our model identifies mechanisms through which fiscal policy operates in SOEs, and incorporates model-consistent expectations. Simulations suggest that the introduction of rational expectations moderates the contractionary effects of public expenditure cuts, but is unlikely to remove them entirely. An alternative explanation of Irelands positive growth experience is proposed, based largely upon external factors.

Where Do Firms Export, How Much, and Why?

The empirical finding that exporting firms are more productive on average than non-exporters has provoked a large theoretical literature based on models such as Melitz (2003), where more productive firms are more likely to overcome costs associated with trade. This paper provides a systematic empirical assessment of the Melitz framework using a unique Irish dataset that includes information on destinations and firm characteristics such as productivity. We find a number of interesting deviations from the model’s predictions including a high degree of unpredictable idiosyncratic participation in export markets by firms, a relatively weak positive correlation between the extent of export participation and export sales, and a limited role for productivity in explaining firm exporting behavior. We illustrate the effect of firm heterogeneity on gravity regressions of aggregate trade flows and show how past exporting to a particular market has a strong impact on the current probability of exporting there.

A Note on the Cointegration of Consumption, Income, and Wealth

Lettau and Ludvigson (2001) argue that a log-linearized approximation to an aggregate budget constraint predicts that log consumption, assets, and labor income will be cointegrated. They conclude that this cointegrating relationship is present in U.S. data, and that the estimated cointegrating residual forecasts future asset growth. This note examines whether the cointegrating relationship suggested by Lettau and Ludvigsons theoretical framework actually exists. We demonstrate that we cannot reject the hypothesis that cointegration is absent from the data once we employ measures of consumption, assets, and labor income that are jointly consistent with an underlying budget constraint. By contrast, Lettau and Ludvigson use a set of variables that do not belong together in an aggregate budget constraint, thereby testing a cointegrating relationship that is not implied by their theory.

Staggered Price Contracts and Inflation Persistence: Some General Results

Despite their popularity as theoretical tools for illustrating the effects of nominal rigidities, some have questioned whether models based on staggered price contracts with rational expectations can match the persistence of the empirical inflation process. This article presents some general results about this class of models. It is shown that these models do not have a problem matching high autocorrelations for inflation. However, they fail to explain a key feature of reduced-form Phillips-curve regressions: The positive dependence of inflation on its own lags. It is shown that staggered price contracting models instead predict that the coefficients on these lag terms should be negative.