Unifying time-to-build theory

Several contributions have recently reconsidered the role of the time to build assumption in explaining some relevant stylized facts. In this paper, the similarities and differences which may emerge when the time to build structure of capital is introduced in a continuous or discrete time framework are studied and enlightened. The most striking difference lies in the dimensionality of the two frameworks, which is always finite in discrete but infinite in continuous time. Then, the deterministic version of the traditional time to build model developed by Kydland and Prescott is presented, and it is shown how the typical time to build model setup in continuous time can be obtained. Moreover, the richest dynamics in continuous time is investigated and, more importantly, it is shown that the predictions in terms of capital, output, and consumption behavior are not signi¯cantly di®erent from its discrete version once the economy is calibrated properly.Discrete and continuous time, time-to-build, mixed functional differential equa- tions.

Endogenous growth and time to build: the AK case.

In this paper an AK growth model is fully analyzed under the time to build assumption. The existence and uniqueness of the (real) balanced growth path and the oscillatory convergence of detrended capital while detrended consumption is constant over time is proved. Moreover the role of transversality conditions and the assumption of capital utilization depending on the time to build coefficient, make these results hold for any value of the delayAK model, Time to build, D-Subdivision method

Increasing Returns to Scale and Welfare: Ranking the Multiple Deterministic Equilibria

We consider a real business cycle model with a productive externality and an aggregate non- convex technology set µa la Benhabib and Farmer embodying capacity utilization, which exhibits indeterminacy of the steady state and multiplicity of deterministic equilibria under plausible values of the increasing returns to scale. The aim of the paper is to rank these different equilibria according to the initial value of consumption using both a linear-quadratic approximation, extensively explained by Benigno and Woodford [2006a, 2006b], and simulation methods. We study the implications of such a ranking in terms of smoothness of the welfare-maximizing trajectory and show that the welfare- maximizing consumption and labor paths are all the smoother since the level of increasing returns is low. At last, we show that this solution provides a good benchmark for judging the desirability of the stabilization policy proposed by Guo and Lansing [1997].Increasing returns, Local indeterminacy, Welfare analysis, Numerical Methods

Some Essays in Growth Theory.

no abstract availableEconomic development;

Optimal policy and consumption smoothing effects in the time-to-build AK model

In this paper the dynamic programming approach is exploited in order to identify the closed loop policy function, and the consumption smoothing mechanism in an endogenous growth model with time to build, linear technology and irreversibility constraint in investment. Moreover the link among the time to build parameter, the real interest rate, and the magnitude of the smoothing effect is deeply investigated and compared with what happens in a vintage capital model characterized by the same technology and utility function. Finally we have analyzed the effect of time to build on the speed of convergence of the main aggregate variables.Time-to-build, AK model, Dynamic programming, optimal

Habits and demand changes after COVID-19

In this paper, we investigate how a transitory lockdown of a sector of the economy may have changed our habits and, therefore, altered the goods’ demand permanently. In a two-sector infinite horizon economy, we show that the demand of the goods produced by the sector closed during the lockdown could shrink or expand with respect to their pre-pandemic level depending on the lockdown’s duration and the habits’ strength. We also show that the end of a lockdown may be characterized by a price surge due to a combination of strong demand of both goods and rigidities in production