M OST models of portfolio selection have been one-period models. I examine the combined problem of optimal portfolio selection and consumption rules for an individual in a continuous-time model where his income is generated by returns on assets and these returns or instantaneous "growth rates" are stochastic. P . A. Samuelson has developed a similar model in discrete-time for more general proba...

Much of recent Trade theory focuses on heterogeneity of firms and the differential impact trade policy might have on firms with different levels of productivity. A common problem is that most firm level dataset do not contain information on output prices of firms which makes it difficult to distinguish between productivity differences and differences in market power between firms. This paper de...

Income is an important correlate for numerous phenomena in the social sciences. But many surveys collect data with just a single question covering all forms of income. This raises questions over the reliability of the data collected. Issues of reliability are heightened when individuals are asked about the household total rather than own income alone. We argue that the large literature on measu...

A new method of decomposing cross-sectional poverty estimates into chronic and transient components is demonstrated using data from a recent household survey in Papua New Guinea. This method is simpler than previously used panel methods because it does not require data on every household in every period. The only requirement is that a subset of the surveyed households have a repeat observation ...

This paper starts from a recent case to study how merger analysis in Europe may potentially be improved through simulation analysis. Starting from the geographic market definition in the Merger Decision, we formulate and estimate an oligopoly model with differentiated products. The model is simulated to account for the changed multiproduct ownership structure after the merger. We show how our f...

Open source software (OSS) is marked by free access to the software and its source code. OSS is developed by a ‘community’ consisting of thousands of contributors from all over the world. Some research was undertaken in order to analyze how global the OSS community actually is, i.e. analyze the geographic origin of OSS developers. But as members of the OSS community differ in their activity lev...

Cumulation of Cross-Section Surveys: Evaluation of Alternative Concepts for the Cumulated Continuous Household Budget Surveys (LWR) 1999 until 2003 Compared to the Sample Survey of Income and Expenditures (EVS) 2003 With the development of household budget systems and with regard to the requirements of the European Union with new EU-SILC approaches, the cumulation of cross-section surveys to an...

Melanoma pathogenesis from normal neural crest-derived melanocytes is often fatal due to aggressive cell invasion throughout the body. The identification of signals that reprogram de-differentiated, metastatic melanoma cells to a less aggressive and stable phenotype would provide a novel strategy to limit disease progression. In this study, we identify and test the function of developmental sig...

The Sound of Others: Surprising Evidence of Conformist Behavior It has been shown that subjects tend to follow others’ behavior even when the external signals are uninformative. In this paper we go one step further, showing that conformism occurs even when the choices of others are not even presented to the subjects, but just indirectly perceived. We use the “Click” version of the Bomb Risk Eli...

Declining response rates to surveys is a widespread and troubling problem. Unit non-response (when a household is not interviewed at all) has been rising in most surveys. For example, unit non-response rates rose by 3-12 percentage points over the 1990s for six U.S. Census Bureau surveys (Atrostic et al. 2001). Many recent papers have raised the concern that this increased non-response has led ...