Power-law weighted networks from local attachments

This letter introduces a mechanism for constructing, through a process of distributed decision-making, substrates for the study of collective dynamics on extended power-law weighted networks with both a desired scaling exponent and a fixed clustering coefficient. The analytical results show that the connectivity distribution converges to the scaling behavior often found in social and engineering systems. To illustrate the approach of the proposed framework we generate network substrates that resemble steady state properties of the empirical citation distributions of (i) publications indexed by the Institute for Scientific Information from 1981 to 1997; (ii) patents granted by the U.S. Patent and Trademark Office from 1975 to 1999; and (iii) opinions written by the Supreme Court and the cases they cite from 1754 to 2002.Comment: 18 pages, 3 figures; Proceedings of the IEEE Conference on Decision and Control and the European Control Conference, Orlando, FL, Dec. 2011; Added references; We modified the model in order to take into account extended power-law distributions which better fit to the citations data sets; Added proofs of theorems; Shorten version; Updated plo

Impact of tax rate cut cum base broadening reforms on heterogeneous firms: Learning from the German tax reform 2008

The German corporate tax reform of 2008 has brought about important cuts in corporate tax rates, which were at the same time accompanied by significant changes in the determination of the tax base for both major German corporate taxes - corporate income tax and trade tax. The reform followed the distinct and internationally prevalent pattern of tax rate cut cum base broadening. Its implications are thus not unique to Germany. Especially in view of the current economic crisis, questions on the distribution of the tax burden among firms of different characteristics have arisen and still remain at the heart of the academic and political debate in Germany and other countries. In this paper we present a new corporate microsimulation model, ZEW TaxCoMM, which allows for the coherent micro-based analysis of revenue implications of tax reforms and the distribution of tax consequences among heterogeneous firms. The model processes firm-level financial accounting input data and derives the firm specific tax base and tax due endogenously in accordance with the tax code. To smooth out distortions between the sample and the population of German corporations, the sample is extrapolated on the basis of the corporate income tax statistic. The simulation results show inter alia that the average annual relief as measured by the average decline in the effective tax burden on cash flow amounts to 2.8 percentage points for large corporations and to 6 percentage points for small corporations. Furthermore, the results illustrate that firms with low profitability, high debt ratio and high capital intensity benefit least from the reform. As to tax revenues, the reform induced decrease amounts to 9.8 billion and the trade tax gains fiscally in importance. --Tax reform,microsimulation,tax policy evaluation

Integrating across memory episodes: Developmental trends

Memory enables us to use information from our past experiences to guide new behaviours, calling for the need to integrate or form inference across multiple distinct episodic experiences. Here, we compared children (aged 9-10 years), adolescents (aged 12-13 years), and young adults (aged 19-25 years) on their ability to form integration across overlapping associations in memory. Participants first encoded a set of overlapping, direct AB- and BC-associations (object-face and face-object pairs) as well as non-overlapping, unique DE-associations. They were then tested on these associations and inferential AC-associations. The experiment consisted of four such encoding/retrieval cycles, each consisting of different stimuli set. For accuracy on both unique and inferential associations, young adults were found to outperform teenagers, who in turn outperformed children. However, children were particularly slower than teenagers and young adults in making judgements during inferential than during unique associations. This suggests that children may rely more on making inferences during retrieval, by first retrieving the direct associations, followed by making the inferential judgement. Furthermore, young adults showed a higher correlation between accuracy in direct (AB, BC) and inferential AC-associations than children. This suggests that, young adults relied closely on AB- and BC-associations for making AC decisions, potentially by forming integrated ABC-triplets during encoding or retrieval. Taken together, our findings suggest that there may be an age-related shift in how information is integrated across experienced episodes, namely from relying on making inferences at retrieval during middle childhood to forming integrated representations at different memory processing stages in adulthood

Apparatus for real-time acoustic imaging of Rayleigh-Benard convection

We have designed and built an apparatus for real-time acoustic imaging of convective flow patterns in optically opaque fluids. This apparatus takes advantage of recent advances in two-dimensional ultrasound transducer array technology; it employs a modified version of a commercially available ultrasound camera, similar to those employed in non-destructive testing of solids. Images of convection patterns are generated by observing the lateral variation of the temperature dependent speed of sound via refraction of acoustic plane waves passing vertically through the fluid layer. The apparatus has been validated by observing convection rolls in both silicone oil and ferrofluid.Comment: 20 pages, 11 figures, submitted to the Review of Scientific Instrument

Construction and application of a questionnaire for the social scientific investigation of environmental noise effects

A social psychological questionnair has been developed to study the effects of environmental noise and was applied to 636 people living in 19 different areas of Hamburg. The theoretical foundations and the statistical means employed in its development are described. Four main reactions to noise are isolated statistically, and it is determined that these are moderated by several intervening variables, chief of which are coping capacity for noise, the perceived dangerousness of the noise souce, other daily loads and the individual's liability

ZEW Corporate Taxation Microsimulation Model (ZEW TaxCoMM)

Current political discussions in Germany and other European countries illustrate the importance accorded to revenue and distribution effects of tax reforms. Whereas widely recognized concepts of effective tax measures can provide important insights into the incentives of taxation they do not allow robust revenue estimations or distribution analyses. Hence there is need to supplement existing quantitative tax models by approaches apt for these issues of policy analysis. Against this background, this paper puts forward a corporate microsimulation model allowing an ex-ante evaluation of tax reforms with regard to distributional consequences and revenue effects. Central feature of the model is the processing of financial statements included in the DAFNE data base of the Bureau van Dijk. The firm-level data is supplemented by survey data on tax accounting practices. The focus of the paper is on the documentation of the model set-up. Its application will be addressed in future publications

Impact of tax rate cut cum base broadening reforms on heterogeneous firms : learning from the German tax reform 2008

The German corporate tax reform of 2008 has brought about important cuts in corporate tax rates, which were at the same time accompanied by significant changes in the determination of the tax base for both major German corporate taxes - corporate income tax and trade tax. The reform followed the distinct and internationally prevalent pattern of tax rate cut cum base broadening. Its implications are thus not unique to Germany. Especially in view of the current economic crisis, questions on the distribution of the tax burden among firms of different characteristics have arisen and still remain at the heart of the academic and political debate in Germany and other countries. In this paper we present a new corporate microsimulation model, ZEW TaxCoMM, which allows for the coherent micro-based analysis of revenue implications of tax reforms and the distribution of tax consequences among heterogeneous firms. The model processes firm-level financial accounting input data and derives the firm specific tax base and tax due endogenously in accordance with the tax code. To smooth out distortions between the sample and the population of German corporations, the sample is extrapolated on the basis of the corporate income tax statistic. The simulation results show inter alia that the average annual relief as measured by the average decline in the effective tax burden on cash flow amounts to 2.8 percentage points for large corporations and to 6 percentage points for small corporations. Furthermore, the results illustrate that firms with low profitability, high debt ratio and high capital intensity benefit least from the reform. As to tax revenues, the reform induced decrease amounts to € 9.8 billion and the trade tax gains fiscally in importance

Assessing the impact of introducing an ACE regime : a behavioural corporate microsimulation analysis for Germany

In their famous Mirrlees review (2011) on reforming the tax system for the 21st century, the authors put forward the introduction of an allowance for corporate equity regime. In recent years, several countries introduced an ACE regime. The main feature of an ACE regime is that it removes tax distortions on marginal investment and finance distortions. Yet, by narrowing the tax base an ACE regime potentially requires an increase in tax rates which might affect location choices and profit shifting activity negatively. In this paper, we employ a microsimulation model to determine the consequences of introducing an ACE regime in Germany. The simulation results show that granting an ACE for corporate income tax purposes results in a revenue loss of about 18%. This could be financed by an increase of the combined profit tax rate by 6 percentage points. At firm level, our analysis illustrates the heterogeneous distribution of the reform effect accross the sample. For 50% of firms between the 25th and 75th percentile, introducing an ACE regime reduces tax payments between 35% and 2%. If the ACE is combined with a tax rate adjustment, the tax effect ranges between -32% and +7.1% for firms between the 25th and 75th percentile. With respect to behavioural responses on decision margins, we find that introducing the ACE reduces the mean debt-ratio by about 1.5 percentage points in the short run. For the capital-stock we arrive at a mean short-term increase of 2.4%. Finally, our computations show that the ACE regime with adjusted profit tax rate cannot be overall tax neutral. In particular, the increase in the profit tax rate required to finance the equity allowance induces intensified outward profit-shifting activities and affects location choices negatively. In the short-run the tax revenue is therefore shown to decline to about 95% of its original level

Profit Shifting and ‘Aggressive' Tax Planning by Multinational Firms: Issues and Options for Reform

This paper discusses the issue of profit shifting and ‘aggressive’ tax planning by multinational firms. The paper makes two contributions. Firstly, we provide some background information to the debate by giving a brief overview over existing empirical studies on profit shifting and by describing arrangements for IP-based profit shifting which are used by the companies currently accused of avoiding taxes. We then show that preventing this type of tax avoidance is, in principle, straightforward. Secondly, we argue that, in the short term, policy makers should focus on extending withholding taxes in an internationally coordinated way. Other measures which are currently being discussed, in particular unilateral measures like limitations on interest and license deduction, fundamental reforms of the international tax system and country-by-country reporting, are either economically harmful or need to be elaborated much further before their introduction can be considered