We propose a new class of observation driven time series models referred to as Generalized Autoregressive Score (GAS) models. The driving mechanism of the GAS model is the scaled score of the likelihood function. This approach provides a unified and consistent framework for introducing...

We document that expansionary monetary policy shocks are less effective at stimulating output and investment in periods of high volatility compared to periods of low volatility, using a regime-switching vector autoregression. The lower effectiveness of monetary policy can be linked to weaker...

Short-time work is a labor market policy that subsidizes working time reductions among firms in financial difficulty to prevent layoffs. Many OECD countries have used this policy in the Great Recession. This paper shows that the effects of short-time work are strongly time dependent and...

This paper uses state-level data to estimate the effect of federal defense spending shocks on state real activity. We find moderately strong evidence that for the average state the fiscal multiplier is larger during recessions. However, there is substantial heterogeneity across the...

This article introduces the concept of co-non-linearity. Co-non-linearity is an example of a common feature in time series (Engle and Koziciki, 1993, J. Bus. Econ. Statist.) and an extension of the concept of common nonlinear components (Anderson and Vahid, 1998, J. Econometrics). If some time...

We introduce a new estimation framework which extends the Generalized Method of Moments (GMM) to settings where a subset of the parameters vary over time with unknown dynamics. To filter out the dynamic path of the time-varying parameter, we approximate the dynamics by an autoregressive process...

We document that expansionary monetary policy shocks are less effective at stimulating output and investment in periods of high volatility compared to periods of low volatility, using a regime-switching vector autoregression. Exogenous policy changes are identified by adapting an external...

Financial shocks generate a protracted and quantitatively important effect on real economic activity and financial markets only if the shocks are both negative and large. Otherwise, their role is quite modest. Financial shocks have become more important for economic fluctuations after the 2000...

Short-time work is a labor market policy that subsidizes working time reductions among firms in financial difficulty in order to prevent layoffs and stabilize employment. Many OECD countries have used this policy in the Great Recession, for example. This paper shows that the effects of...

We introduce a new estimation framework which extends the Generalized Method of Moments (GMM) to settings where a subset of the parameters vary over time with unknown dynamics. To filter out the dynamic path of the time-varying parameter, we approximate the dynamics by an autoregressive process...