Merger Policy and Tax Competition

In many situations governments have sector-specific tax and regulation policies at their disposal to influence the market outcome after a national or an international merger has taken place. In this paper we study the implications for merger policy when countries non-cooperatively deploy production-based taxes. We find that whether national or international mergers are more likely to be enacted in the presence of nationally optimal tax policies depends crucially on the ownership structure of firms. When all firms are owned domestically in the pre-merger situation, non-cooperative tax policies are more efficient in the national merger case and smaller synergy effects are needed for this type of merger to be proposed and cleared. These results are reversed when there is a high degree of foreign firm ownership prior to the merger

Finite domain constraint programming systems

Tutorial at CP'2002, Principles and Practice of Constraint Programming. Powerpoint slides.</p

Business R&D expenditure and capital in Europe

This study presents new estimates of business R&D capital stocks for 22 countries at the aggregate and industry levels. At 9 percent of GDP, the EU business R&D capital stock falls short of its US and Japanese counterparts. Within the EU, R&D capital stocks are much lower in the southern and the new member states, reflecting large and persistent disparities in R&D expenditure. There was hardly any convergence over the past decade. The R&D capital stock is concentrated on three technologyintensive manufacturing industries and is positively correlated with growth in total factor productivity across countries and industries. Finally, the ratios between the stocks of R&D capital and tangible capital suggest marked differences in how R&D and tangible capital are combined in production.R&D capital stock; R&D expenditure; tangible capital stock; R&D intensity; high-tech manufacturing

Survey on Combinatorial Register Allocation and Instruction Scheduling

Register allocation (mapping variables to processor registers or memory) and instruction scheduling (reordering instructions to increase instruction-level parallelism) are essential tasks for generating efficient assembly code in a compiler. In the last three decades, combinatorial optimization has emerged as an alternative to traditional, heuristic algorithms for these two tasks. Combinatorial optimization approaches can deliver optimal solutions according to a model, can precisely capture trade-offs between conflicting decisions, and are more flexible at the expense of increased compilation time. This paper provides an exhaustive literature review and a classification of combinatorial optimization approaches to register allocation and instruction scheduling, with a focus on the techniques that are most applied in this context: integer programming, constraint programming, partitioned Boolean quadratic programming, and enumeration. Researchers in compilers and combinatorial optimization can benefit from identifying developments, trends, and challenges in the area; compiler practitioners may discern opportunities and grasp the potential benefit of applying combinatorial optimization

Merger Policy and Tax Competition

In many situations governments have sector-specific tax and regulation policies at their disposal to influence the market outcome after a national or an international merger has taken place. In this paper we study the implications for merger policy when countries non-cooperatively deploy production-based taxes. We find that whether national or international mergers are more likely to be enacted in the presence of nationally optimal tax policies depends crucially on the ownership structure of firms. When all firms are owned domestically in the pre-merger situation, non-cooperative tax policies are more efficient in the national merger case and smaller synergy effects are needed for this type of merger to be proposed and cleared. These results are reversed when there is a high degree of foreign firm ownership prior to the merger.merger regulation; tax competition

Rare Earth Element Patterns in Conodont Apatite from the Upper Ordovician: Testing Enrichment Sources and Possible Oceanographic Changes

The Mohawkian series of the Middle Late Ordovician was a time of great lithological and faunal changes that coincide with a positive ä13C excursion known as the Guttenberg Isotopic Carbon Excursion (GICE). Two prevailing hypotheses have been proposed to explain the cause of these changes. The “cold-water” hypothesis suggests that global cooling caused the tropical belt to shrink and cold water to invade the epicontinental sea while the “tectonic-forcing” hypothesis suggests that increased weathering rates led to basinal deepening, resulting in cooler oceanic waters invading the midcontinent sea. This study tests if regional tectonics caused by the Taconic Orogeny led to an invasion of cool ocean water into the epicontinental sea using rare earth elements (REEs). Additionally, this research analyzes the potential REE enrichment sources to determine the level of diagenesis and to better determine paleoceanographic conditions. The hypothesis of this research states that REE values from the Dickeyville, Wisconsin section will exhibit a shift through time from “HREE-depleted” patterns to “HREE enriched” patterns. The “HREE-depleted” pattern would indicate that the shallow carbonate platform experienced LREE and MREE enrichment due to sediment deposition dominating the seawater signal. The transition to a “HREE enriched” REE pattern would coincide with a decrease in sediment deposition as basinal deepening occurs and seawater became the dominant REE enrichment source. Rare earth element concentrations were measured using an LA-ICP-MS on four conodont species prevalent in Dickeyville, WI with attention to the three types conodont tissues as well. The Dickeyville conodonts experienced REE enrichment from high terrigenous influx, which overprinted the “true” seawater REE signal. Additionally, REE profiles indicate that K-bentonite deposits played a role in REE enrichment in the stratigraphically associated intervals and that sediment from a mix of sources is the primary source for REEs with occasional inputs from weathered magmas originating from the Transcontinental Arch and Precambrian shield. Due to the terrigenous overprinting and ashbed REE enrichment, the redox and oceanographic changes at the Dickeyville section could not be definitively interpreted. Therefore, REE analysis from the Dickeyville section does not indicate that tectonics played a role in the Upper Ordovician changes

Design Rules in VLSI Routing

One of the last major steps in the design of highly integrated circuits (VLSI design) is routing. The task of routing is to compute disjoint sets of wires connecting different parts of a chip in order to realize the desired electrical connectivity. Design rules define restrictions on the minimum distance and geometry of metal shapes. The intent of most design rules is to forbid patterns that cannot be manufactured well in the lithographic production process. This process has become extremely difficult with the current small feature sizes of 32 nm and below, which are still being manufactured using 193 nm wavelength technology. Because of this, the design rules of modern technologies have become very complex, and computing a routing with a sufficiently low number of design rule violations is a difficult task for automated routing tools. In this thesis we present in detail how design rules can be handled efficiently. We develop an appropriate design rule model which considerably reduces complexity while not being too restrictive. This involves mapping complex polygon-based rules to simpler rectangle-based rules and building equivalence classes of shapes with respect to their minimum distance requirements. Our model enables efficient checking of minimum distance rules, which has to be done dozens of times in each routing run. We also discuss efficient data structures that are necessary to achieve this. We implemented our design rule model within BonnRoute, the routing tool of the BonnTools, a software package for VLSI physical design developed at the Research Institute for Discrete Mathematics at the University of Bonn in cooperation with IBM. The result is a new module of BonnRoute, called BonnRoutRules, which computes this design rule model and embeds BonnRoute in the complex routing environment of current technologies. The BonnRouteRules module was a key part in enabling BonnRoute to route current 32 nm and 22 nm chips. We describe the combined routing flow used by IBM in practice, in which BonnRoute solves the main routing task and an industrial standard router is used for postprocessing. We present detailed experimental results of this flow on real-world designs. The results show that this combined flow produces routings with almost no remaining design rule violations, which proves that our design rule model works well in practice. Furthermore, compared to the industrial standard router alone, the combination with BonnRoute provides several significant benefits: It has 24% less runtime, 5% less wiring length, and over 90% less detours, which shows that with this flow we have an excellent routing tool in practice