Market regulation, labor policies and the wage-productivity gap

This paper proposes an empirical analysis about the influence of some institutional factors (taxation, active and passive labor market policies, labor and goods market regulation and unions’ participation) on the component of the wage growth not explained by the productivity growth (WP gap, thereafter). We consider a 14 OECD countries Panel Data over the period 1983-2003, using four different estimations: fixed effects vector decomposition (FEVD), fixed effects (FE), random effects (RE) and feasible general least square (FGLS). Results for all estimations show that the WP gap is affected by tax wedge, active labor market policies, employment protection for temporary workers and union density, while product market regulation and passive labor market policies do not play a significant role

Do labor market conditions affect the strictness of employment protection legislation?

We provide a theoretical microfoundation for the negative relationship between firing costs and labor market tightness and its effects on labor market performance. The optimal level of firing costs is chosen by the employed worker i.e. the insider by maximizing her human capital. Performing a comparative statics exercise, we analyze the effects of labor market tightness on the optimal choice of firing costs. The results are clear cut and allow to obtain a decreasing firing costs function in the labor market tightness. Moreover, we show that this negative relationship can give rise to a labor market configuration characterized by multiple equilibria: prolonged average duration of unemployment will produce a labor market with low flows and high strictness of employment protection, and vice versa.Matching Models

NLS ground states on graphs

We investigate the existence of ground states for the subcritical NLS energy on metric graphs. In particular, we find out a topological assumption that guarantees the nonexistence of ground states, and give an example in which the assumption is not fulfilled and ground states actually exist. In order to obtain the result, we introduce a new rearrangement technique, adapted to the graph where it applies. Owing to such a technique, the energy level of the rearranged function is improved by conveniently mixing the symmetric and monotone rearrangement procedures.Comment: 24 pages, 4 figure

Nonlinear dynamics on branched structures and networks

Nonlinear dynamics on graphs has rapidly become a topical issue with many physical applications, ranging from nonlinear optics to Bose-Einstein condensation. Whenever in a physical experiment a ramified structure is involved, it can prove useful to approximate such a structure by a metric graph, or network. For the Schroedinger equation it turns out that the sixth power in the nonlinear term of the energy is critical in the sense that below that power the constrained energy is lower bounded irrespectively of the value of the mass (subcritical case). On the other hand, if the nonlinearity power equals six, then the lower boundedness depends on the value of the mass: below a critical mass, the constrained energy is lower bounded, beyond it, it is not. For powers larger than six the constrained energy functional is never lower bounded, so that it is meaningless to speak about ground states (supercritical case). These results are the same as in the case of the nonlinear Schrodinger equation on the real line. In fact, as regards the existence of ground states, the results for systems on graphs differ, in general, from the ones for systems on the line even in the subcritical case: in the latter case, whenever the constrained energy is lower bounded there always exist ground states (the solitons, whose shape is explicitly known), whereas for graphs the existence of a ground state is not guaranteed. For the critical case, our results show a phenomenology much richer than the analogous on the line.Comment: 47 pages, 44 figure. Lecture notes for a course given at the Summer School "MMKT 2016, Methods and Models of Kinetic Theory, Porto Ercole, June 5-11, 2016. To be published in Riv. Mat. Univ. Parm

Fiscal policy response to the COVID-19 pandemic in the euro area

We estimate the impact of fiscal measures adopted in response to the Covid-19 crisis at the euro area level, combining standard macroeconomic data with an index on the strictness of ‘lockdown style’ policies. Given the multitude of shocks occurred simultaneously during the pandemic, the fiscal stimulus is identified together with other supply- and demand-side shocks using a sign and zero restricted Bayesian vector autoregressive (VAR) model. Our results show that during the two years 2020-2021, public spending and revenue-side measures avoided a further reduction of GDP equal to 2.8 and 0.9 percentage points, respectively

Dimensional crossover with a continuum of critical exponents for NLS on doubly periodic metric graphs

We investigate the existence of ground states for the focusing nonlinear Schroedinger equation on a prototypical doubly periodic metric graph. When the nonlinearity power is below 4, ground states exist for every value of the mass, while, for every nonlinearity power between 4 (included) and 6 (excluded), a mark of $L^2$-criticality arises, as ground states exist if and only if the mass exceeds a threshold value that depends on the power. This phenomenon can be interpreted as a continuous transition from a two-dimensional regime, for which the only critical power is 4, to a one-dimensional behavior, in which criticality corresponds to the power 6. We show that such a dimensional crossover is rooted in the coexistence of one-dimensional and two-dimensional Sobolev inequalities, leading to a new family of Gagliardo-Nirenberg inequalities that account for this continuum of critical exponents.Comment: 17 pages, 2 figure