Calder\'on-Zygmund estimates for higher order systems with p(x) growth

For weak solutions $u \in W^{m,1}(\Omega;\R^N)$ of higher order systems of the type \int_\Omega dx = \int_\Omega < |F|^{p(x)-2}F,D^m \phi> dx, for all $\phi \in C^{\infty}_c(\Omega;\R^N), m > 1$ with variable growth exponent $p:\Omega \to (1,\infty)$ we prove that if $|F|^{p(\cdot)} \in L^q_{loc}(\Omega)$ with $1 < q < \frac{n}{n-2} + \delta$, then $|D^m u|^{p(\cdot)} \in L^q_{loc}(\Omega)$. We should note that we prove this implication both in the non-degenerate and in the degenerate case.Comment: 29 page

Regularity results for a class of obstacle problems under non standard growth conditions

We prove regularity results for minimizers of functionals F(u, Ω) := ∫Ω f(x, u, Du) dx in the class K := {u ∈ W1,p(x)(Ω, R) : u ≥ ψ}, where ψ : Ω → R is a fixed function and f is quasiconvex and fulfills a growth condition of the type L−1|z|p(x) ≤ f(x, ξ, z) ≤ L(1 + |z|p(x)), with growth exponent p : Ω → (1, ∞)

Determinants of agricultural cash rents in Germany: A spatial econometric analysis for farm-level data

We empirically analyse the determinants of cash rent levels for agricultural land in Lower Saxony, Germany. We are the first to apply a spatial econometrics approach that accounts for two types of spatial dependence simultaneously to cash rent data at the farm-level. Our empirical results underline the usefulness of such an approach. Farm characteristics which serve as a proxy for the marginal value of rented acreage for the tenant as well as variables which represent local competition on the land market are significant. Among the farm characteristics, operating revenue per hectare, share of high-value crops, soil quality, share of rented acreage, share of arable land relative to rented acreage, and animal density are significant while, ceteris paribus, neither labour nor machinery/buildings per hectare nor farm size are significant. In particular, animal density at the regional level increases the cash rent, underlining the importance of local competition on the land market. The analysis also shows that subsidies which foster competition among farmers for rented land boost landlords’ incomes. Thus, evaluation of set-aside programs or evaluation of public support for investment in pig or poultry production or renewable energies has to take such side-effects into account.Cash rent, farm-level data, spatial econometrics, Land Economics/Use,

Risk Sharing and Efficiency Implications of Progressive Pension Arrangements

The present paper aims to quantify the welfare effects of progressive pension arrangements in Germany. Starting from a purely contribution-related benefit system, we introduce basic allowances for contributions and a flat benefit fraction. Since our overlapping-generations model takes into account variable labor supply, borrowing constraints as well as stochastic income risk, we can compare the labor supply, the liquidity, and the insurance effects of the policy reform. Our simulations indicate that for a realistic parameter combination an increase in pension progressivity would yield an aggregate efficiency gain of more than 2 percent of resources. However, such a reform would not be implemented because it would not find political support of the currently living generations.pension reform, idiosyncratic labor income uncertainty

Private Retirement Savings in Germany: The Structure of Tax Incentives and Annuitization

The present paper studies the growth, welfare and efficiency consequences of the recent introduction of tax-favored retirement accounts in Germany in a general equilibrium overlapping generations model with idiosyncratic lifespan and labor income uncertainty. We focus on the implicit differential taxation of specific savings motives, the mandatory annuitization of benefits and the impact of special provisions for low-income households. The simulations indicate that the reform improves overall economic efficiency by about 0.6 percent of aggregate resources, but welfare decreases significantly for future generations. Finally, we show that special provisions could be very effective in raising the participation of low-income households despite their low budgetary cost.individual retirement accounts, annuities, stochastic general equilibrium