An ah-initio calculation is made on a resonant state of the H2 ~ ion hy an approximate variation method. Excellent agreement \ experiment is obtained. Physical justification is given for the use of the approximate variation method.

Liquid-liquid extraction of sulfuric acid using tri-n-dodecylamine/kerosene

comments. A special thanks to Sanjay Jain, with whom I am collaborating on related theoretical

During financial disruptions, marketmakers provide liquidity by absorbing external selling pressure. They buy when the pressure is large, accumulate inventories, and sell when the pressure alleviates. This paper studies optimal dynamic liquidity provision in a theoretical market setting with large and temporary selling pressure, and order-execution delays. I show that competitive marketmakers offer the socially optimal amount of liquidity, provided they have access to sufficient capital. If raising capital is costly, this suggests a policy role for lenient centralbank lending during financial disruptions.

at the SED meeting (Paris, 2003), T2M (Orléans, 2004), SCSE congress (Québec, 2004),

of the fruits of this approach, we discuss the concept of `articulation work' and its relevance to CSCW. This raises a host of interesting problems that are marginalized in the work on small group support but critical to the success of CSCW systems `in the large', i. e., that are designed to meet

assistance. All errors are ours. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject

Preliminary draft, comments welcome. ∗We are grateful to participants at the DIW Conference on Aging, Saving and Retirement, the SAVE

This paper contributes to the investigation of employer-to-employer mobility across the career of wage maximizing individuals. The mobility model derived here is establishing the benchmark for optimal transitions. Furthermore, gener-alizations provide an explanation for the coexistence of wage reductions and wage markups induced by mobility. The empirical investigation, based on German linked employer-employee data, is on estimating counterfactual wage trajectories to con-clude whether the between-firm wage path exceeds the within-firm wage trajec-tory. Hence, an evaluation of the performance of individual employer-to-employer mobility is conducted. The results show that most of the employer-to-employer transitions are accompanied by wage losses.

laboratory for fruitful discussions and D. Venzke and