"The Way in which an Experiment is Conducted is Unbelievably Important": On the Experimentation Practices of Economists and Psychologists

To discuss experimental results without discussing how they came about makes sense when the results are robust to the way experiments are conducted. Experimental results, however, are – arguably more often than not – sensitive to numerous design and implementation characteristics such as the use of financial incentives, deception, and the way information is presented. To the extent that economists and psychologists have different experimental practices, this claim is of obvious practical and interpretative relevance. In light of the empirical results summarized below, it seems warranted to say that it does not make sense to report experimental results without reporting the design and implementation choices that were made.Duhem-Quine problem, experimental design, experimental implementation, financial incentives, deception

Bertrand Price Undercutting: A Brief Classroom Demonstration

I present a brief classroom demonstration illustrating Bertrand price undercutting. The classroom demonstration is appropriate for Micro Principles, and both intermediate and upper level undergraduate, as well as graduate classes in micro, Industrial Organization, and Game Theory.

'The Way in Which an Experiment is Conducted is Unbelievably Important': On the Experimentation Practices of Economists and Psychologists

To discuss experimental results without discussing how they came about makes sense when the results are robust to the way experiments are conducted. Experimental results, however, are – arguably more often than not – sensitive to numerous design and implementation characteristics such as the use of financial incentives, deception, and the way information is presented. To the extent that economists and psychologists have different experimental practices, this claim is of obvious practical and interpretative relevance. In light of the empirical results summarized below, it seems warranted to say that it does not make sense to report experimental results without reporting the design and implementation choices that were made.Duhem-Quine problem; experimental design; experimental implementation; financial incentives; deception

Splitting of the Zero-Energy Landau Level and Universal Dissipative Conductivity at Critical Points in Disordered Graphene

We report on robust features of the longitudinal conductivity ($\sigma_{xx}$) of the graphene zero-energy Landau level in presence of disorder and varying magnetic fields. By mixing an Anderson disorder potential with a low density of sublattice impurities, the transition from metallic to insulating states is theoretically explored as a function of Landau-level splitting, using highly efficient real-space methods to compute the Kubo conductivities (both $\sigma_{xx}$ and Hall $\sigma_{xy}$). As long as valley-degeneracy is maintained, the obtained critical conductivity $\sigma_{xx}\simeq 1.4 e^{2}/h$ is robust upon disorder increase (by almost one order of magnitude) and magnetic fields ranging from about 2 to 200 Tesla. When the sublattice symmetry is broken, $\sigma_{xx}$ eventually vanishes at the Dirac point owing to localization effects, whereas the critical conductivities of pseudospin-split states (dictating the width of a $\sigma_{xy}=0$ plateau) change to $\sigma_{xx}\simeq e^{2}/h$, regardless of the splitting strength, superimposed disorder, or magnetic strength. These findings point towards the non dissipative nature of the quantum Hall effect in disordered graphene in presence of Landau level splitting

Promoting competitiveness in South African agriculture and agribusiness: The role of institutions

This paper considers private and public institutions that will help promote the competitiveness of commercial farms and agribusiness firms, and enhance the productivity of communal farmers and the competitiveness of emerging farmers in South Africa. Commercial agriculture and agribusiness are creating institutions (such as food safety standards and strategic partnerships), adopting existing private and public institutions (e.g. TQM, ISO 9000 and HACCP) or restructuring to add value to products and services, reduce costs and gain access to export markets. Government should focus its relatively scarce resources on providing physical and legal infrastructure (such as secure property rights and contract enforcement) to reduce transaction costs, including risk, so that markets work efficiently. A major challenge for local agricultural economists is to provide information about institutions that will promote the productive use of land in communal areas, and the competitiveness of emerging farmers on redistributed commercial farmland.Agribusiness, International Relations/Trade,