Sind Nominallöhne starr? Neuere Evidenz und wirtschaftspolitische Implikationen

In the presence of downwardly rigid nominal wages, low inflation may lead to higher equilibrium unemployment by hindering real wage adjustments. This article surveys and analyses the growing evidence on downwardly rigid nominal wages. We not only deal with assessments of the existence and extent of downward nominal wage rigidity, but also discuss its possible explanations and macroeconomic consequences. We conclude that downward nominal wage rigidity does exist, that its extent is substantial and that very likely the real consequences at low, close to zero inflation are non-negligible. The results of this strand of research should therefore be taken into account in the formulation of optimal inflation targets

Artificial Immune System-based algorithm for vehicle routing problem with time window constraint for the delivery of agri-fresh produce

This paper addresses the problem of delivering continuously deteriorating agri-fresh produce from a wholesaler to a number of retailers, within specific time windows. The prime objective is to decide the routes in such a way that the overall cost incurred in transportation, deterioration and penalty is minimised. To model these conflicting objectives a mathematical modelling approach is proposed. The Vehicle Routing Problem with Time Windows (VRPTW) is a Non-deterministic Polynomial-time hard (NP-hard) problem, without considering the business constraints, and becomes computationally prohibitive with the increase in number of retailers. To solve the VRPTW within feasible time limits, Artificial Immune System (AIS)-based solution methodology is proposed. The algorithm is tested on real-life instances generated from Azadpur wholesale market, New Delhi (India). An experiment is performed on the same problems with other algorithms, such as Genetic Algorithm (GA) and Simulated Annealing (SA), to compare the effectiveness and efficiency of the proposed approach. It is found from the quality of solution and rate of convergence that AIS performed better compared to the other applied approaches