Cluster Monte Carlo Algorithms for Dissipative Quantum Systems

We review efficient Monte Carlo methods for simulating quantum systems which couple to a dissipative environment. A brief introduction of the Caldeira-Leggett model and the Monte Carlo method will be followed by a detailed discussion of cluster algorithms and the treatment of long-range interactions. Dissipative quantum spins and resistively shunted Josephson junctions will be considered.Comment: to be publushed in Proceedings of the Yukawa Symposium 200

Aid, Governance, and Private Foreign Investment: Some Puzzling Findings and a Possible Explanation

Does offcial aid pave the road for private foreign investment or does it suffocate private initiative by diverting resources towards unproductive activities? In this paper we explore this question using data for a large number of developing and emerging economies. Controlling for countries’ institutional environment, we find that, evaluated at the mean, the marginal effect of aid on private foreign investment is close to zero. Surprisingly, however, the effect is strictly positive for countries in which private agents face a substantial regulatory burden. After testing the robustness of this result, we offer a theoretical model that is able to rationalize our puzzling observation.

The Macroeconomic Effects of Foreign Aid: A Survey

Research on the macroeconomic effects of aid has expanded rapidly in recent years. In this paper, we provide a survey of this literature. We start by reviewing some theoretical models that suggest a positive impact of aid on investment and growth. We then discuss the empirical evidence, giving particular attention to the role of institutions and policies in determining aid effectiveness. As a general conclusion, we suggest adopting a more disaggregate perspective with respect both to different types of aid and to various aspects of governance.foreign aid, economic growth, institutions, governance

Deciding to Peg the Exchange Rate in Developing Countries:The Role of Private-Sector Debt

We argue that a higher share of the private sector in a country’s external debt raises the incentive to stabilize the exchange rate. We present a simple model in which exchange rate volatility does not affect agents’ welfare if all the debt is incurred by the government. Once we introduce private banks who borrow in foreign currency and lend to domestic firms, the monetary authority has an incentive to dampen the distributional consequences of exchange rate fluctuations. Our empirical results support the hypothesis that not only the level, but also the composition of foreign debt matters for exchange-rate policy.

“Yes, (s)he is pretty, but...” An investigation of the simultaneous impact of endorser characteristics relevant to purchasing behaviour

Objectives. Research on advertising efficiency states, that both the attractiveness of a model endorsing a product (Halliwell & Dittmar, 2004) as well as the extent of identification with this endorser (Felser, 2001) are relevant parameters of advertising effectiveness. Surprisingly, no research has simultaneously investigated the significance of attractiveness and identification with the endorser in the field of non-celebrity endorsement (e.g., typical product users), so far. Method and Results. Using an experimental between-subjects design (N = 480) endorser’s attractiveness and gender were manipulated in print advertisements for four different products. Including pivotal determinants of purchasing behaviour (e.g., impression on product quality) multiple regression analysis showed that identification but not attractiveness had a small but significant incremental predictive value on purchasing behaviour. Conclusion. A (potentially less attractive) non-celebrity endorser with whom consumers can identify themselves might be preferred in favour of an attractive one with whom consumers cannot identify themselves

Continuous-time auxiliary field Monte Carlo for quantum impurity models

We present a continuous-time Monte Carlo method for quantum impurity models, which combines a weak-coupling expansion with an auxiliary-field decomposition. The method is considerably more efficient than Hirsch-Fye and free of time discretization errors, and is particularly useful as impurity solver in large cluster dynamical mean field theory (DMFT) calculations.Comment: 6 pages, 5 figure