Research Output
1 - 10 of 12
Publication
New tests of the New-Keynesian Phillips Curve
2001-06-26, Whelan, Karl, Rudd, Jeremy
Is 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.
Publication
Can rational expectations sticky-price models explain inflation dynamics?
2006-03, Whelan, Karl, Rudd, Jeremy
The canonical inflation specification in sticky-price rational expectations models (the new-Keynesian Phillips curve) is often criticized for failing to account for the dependence of inflation on its own lags. In response, many studies employ a “hybrid” specification in which inflation depends on its lagged and expected future values, together with a driving variable such as the output gap. We consider some simple tests of the hybrid model that are derived from its closed form. We find that the hybrid model describes inflation dynamics poorly, and find little empirical evidence for the type of rational, forward-looking behavior that the model implies.
Publication
A note on the cointegration of consumption, income, and wealth
2002-11, Rudd, Jeremy, Whelan, Karl
Lettau 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.
Publication
Inflation targets, credibility, and persistence in a simple sticky-price framework
2003-07-23, Whelan, Karl, Rudd, Jeremy
This paper presents a re-formulated version of a canonical 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 analyze 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.
Publication
Empirical proxies for the consumption–wealth ratio
2006, Rudd, Jeremy, Whelan, Karl
Using 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.
Publication
Inflation targets, credibility and persistence in a simple sticky-price framework
2003-08, Rudd, Jeremy, Whelan, Karl
An 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.
Publication
Modelling inflation dynamics : a critical review of recent research
2005-11, Rudd, Jeremy, Whelan, Karl
In 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.
Publication
Modeling inflation dynamics : a critical review of recent research
2007-02, Rudd, Jeremy, Whelan, Karl
In 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.
Publication
Can rational expectations sticky-price models explain inflation dynamics
2003-08, Rudd, Jeremy, Whelan, Karl
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 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.
Publication
Does labor's share drive inflation?
2005-04, Rudd, Jeremy, Whelan, Karl
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.