This paper analyzes the possibility of expectations-driven business cycles to emerge in a one-sector real business cycle model if the unique driving force is news about future income tax rates. We find that good news about labor income tax rates cannot generate expectations-driven business cycles, whereas good news about capital income tax rates can. We show that a one-sector real business cycle model enriched with (i) variable capital utilization and (ii) investment adjustment costs and driven solely by news shocks about capital income tax rates is able to generate qualitatively and quantitatively realistic business cycle fluctuations. In contrast to numerous studies in the news-driven business cycle literature, our model maintains separable preferences.

In a model where banks face a capital sufficiency requirement, we demonstrate that news about a fall in the expected return on a portfolio of international long bonds held by a bank leads to an immediate and persistent fall in economic activity. Even if the news never materializes, economic activity falls below steady state for several periods, followed by a recovery. The portfolio adjustment induced by the capital sufficiency requirements leads to a rise in loan rates and tighter credit conditions, which trigger the fall in activity. We contribute to the news-shock literature by showing that imperfect signals about future financial returns can create business cycles without relying on the usual suspects—shocks to technology, preferences, or fiscal policy—and to the emerging economy business cycle literature in that disturbances in world financial markets can cause domestic business cycles without shocks to the world interest rate or to country spreads.

We investigate the role of nonseparable preferences in the occurrence of macroeconomic instability under a balanced-budget rule where government spending is financed by a tax on labor income. Considering a one-sector neoclassical growth model with a large class of nonseparable utility functions, we find that expectations-driven fluctuations occur easily when consumption and labor are Edgeworth substitutes or weak Edgeworth complements. Under these assumptions, an intermediate range of tax rates and a sufficiently low elasticity of intertemporal substitution in consumption lead to instability.