Now showing 1 - 10 of 13
- PublicationCan rational expectations sticky-price models explain inflation dynamicsRecent 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 model's 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.
- PublicationInflation targets, credibility and persistence in a simple sticky-price frameworkAn important trend in macroeconomic research in recent years involves the increased use of optimization-based models with nominal rigidities (such as sticky prices) to analyse how monetary policy affects the economy and how optimal policy should be designed. This paper presents a re-formulated version of a commonly-used baseline sticky-price model that has been extended to account for variations over time in the central bank's inflation target. We derive a closed-form solution for the model and analyse its properties under various parameter values. The model is used to explore topics relating to the effects of disinflationary monetary policies and inflation persistence. In particular, we employ the model to illustrate and assess the critique that standard sticky-price models generate counterfactual predictions for the effects of monetary policy.
- PublicationDoes 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.
- PublicationNew tests of the New-Keynesian Phillips CurveIs the observed correlation between current and lagged inflation a function of backward-looking inflation expectations, or do the lags in inflation regressions merely proxy for rational forward-looking expectations, as in the new-Keynesian Phillips curve? Recent research has attempted to answer this question by using instrumental variables techniques to estimate "hybrid" specifications for inflation that allow for effects of lagged and future inflation. We show that these tests of forward-looking behavior have very low power against alternative, but non-nested, backward-looking specifications, and demonstrate that results previously interpreted as evidence for the new-Keynesian model are also consistent with a backward-looking Phillips curve. We develop alternative, more powerful tests, which find a very limited role for forward-looking expectations.
- PublicationA note on the cointegration of consumption, income, and wealthLettau and Ludvigson (2001) argue that a log-linearized approximation to an aggregate budget constraint predicts that log consumption, assets, and labour 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 Ludvigson's 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.
- PublicationOn the relationships between real consumption, income, and wealthThe 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.
- PublicationDoes the labour share of income drive inflation?Woodford (2001) has presented evidence that the new-Keynesian Phillips curve fits 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. He concludes 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 the labor share. 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.
- PublicationModelling inflation dynamics : a critical review of recent researchIn recent years, a broad academic consensus has arisen around the use of rational expectations sticky-price models to capture inflation dynamics. These models are seen as providing an empirically reasonable characterization of observed inflation behavior once suitable measures of the output gap are chosen; and, moreover, are perceived to be robust to the Lucas critique in a way that earlier econometric models of inflation are not. We review the principal conclusions of this literature concerning: 1) the ability of these models to fit the data; 2) the importance of rational forward-looking expectations in price setting; and 3) the appropriate measure of inflationary pressures. We argue that existing rational expectations sticky-price models fail to provide a useful empirical description of the inflation process, especially relative to traditional econometric Phillips curves of the sort commonly employed for policy analysis.
- PublicationEmpirical proxies for the consumption–wealth ratioUsing a log-linearized approximation to an aggregate budget constraint, it is possible to show that the ratio of consumption to total (human and non-human) wealth summarizes agents' expectations concerning both future labor income and future asset returns. In a series of recent papers, Lettau and Ludvigson construct an empirical analogue to the consumption–wealth ratio by approximating total wealth with a linear combination of labor income and observable non-human wealth. If valid, this framework suggests that consumption, assets, and labor income will be cointegrated. We demonstrate, however, that standard tests fail to reject the hypothesis of no cointegration once one employs measures of consumption, assets, and labor income that are jointly consistent with an underlying budget constraint. We also show that deviations of consumption, assets, and income from an estimated common trend are unable to predict future excess returns on stocks out of sample once theoretically consistent measures are used.
684Scopus© Citations 25
- PublicationModeling inflation dynamics : a critical review of recent researchIn recent years, a broad academic consensus has arisen that favors using rational expectations sticky-price models to capture inflation dynamics. We review the principal conclusions of this literature concerning: (1) the ability of these models to fit the data; (2) the importance of rational forward-looking expectations in price setting; and (3) the appropriate measure of inflationary pressures. We argue that existing models fail to provide a useful empirical description of the inflation process.
2231Scopus© Citations 126