Complexity of Model Testing for Dynamical Systems with Toric Steady States

In this paper we investigate the complexity of model selection and model testing for dynamical systems with toric steady states. Such systems frequently arise in the study of chemical reaction networks. We do this by formulating these tasks as a constrained optimization problem in Euclidean space. This optimization problem is known as a Euclidean distance problem; the complexity of solving this problem is measured by an invariant called the Euclidean distance (ED) degree. We determine closed-form expressions for the ED degree of the steady states of several families of chemical reaction networks with toric steady states and arbitrarily many reactions. To illustrate the utility of this work we show how the ED degree can be used as a tool for estimating the computational cost of solving the model testing and model selection problems

International Trade: Rules of Origin

[Excerpt] Determining the country of origin of a product is important for properly assessing tariffs, enforcing trade remedies (such as anti-dumping and countervailing duties) or quantitative restrictions (tariff quotas), and statistical purposes. Other commercial trade policies are also linked with origin determinations, such as country of origin labeling and government procurement regulations. Rules of origin (ROO), used to determine the country of origin of merchandise entering the U.S. market, can be very simple, noncontroversial tools of international trade as long as all of the parts of a product are manufactured and assembled primarily in one country. However, when a finished product’s component parts originate in many countries, as is often the case in today’s global trading environment, determining origin can be a very complex, sometimes subjective, and time-consuming process. U.S. Customs and Border Protection (CBP) is the agency responsible for determining country of origin using various ROO schemes. Non-preferential rules of origin are used to determine the origin of goods imported from countries with which the United States has most-favored-nation (MFN) status. They are the principal regulatory tools for accurate assessment of tariffs on imports, addressing country of origin labeling issues, qualifying goods for government procurement, and enforcing trade remedy actions and trade sanctions. Preferential rules are used to determine the eligibility of imported goods from certain U.S. free trade agreement (FTA) partners and certain developing country beneficiaries to receive duty-free or reduced tariff benefits under bilateral or regional FTAs, trade preference programs (such as the Generalized System of Preferences), and other special import programs. Preferential rules of origin are specific to each FTA, which means that they vary from agreement to agreement and preference to preference. This report deals with ROO in three parts. First, we describe in more detail the reasons that country of origin rules are important and briefly describe U.S. laws and methods that provide direction in making these determinations. Second, we discuss briefly some of the more controversial issues involving rules of origin, including the apparently subjective nature of some CBP origin determinations, and the effects of the global manufacturing process on ROO. Third, we conclude with some alternatives and options that Congress could consider that might assist in simplifying the process. This report will be updated as events warrant

International Trade: Rules of Origin

[Excerpt] Recent trade policy issues have pointed to the framework used by the United States and other countries to regulate imports, including the process of determining country of origin using “rules of origin” (ROO). Such rules can be very simple, noncontroversial tools of international trade as long as all of the parts of a product are manufactured and assembled primarily in one country. However, when a finished product’s component parts originate in many countries—as is often the case in today’s global trading environment—determining origin can be a very complex, sometimes subjective, and time-consuming process. This report first provides a general overview of the U.S. ROO system, including its implementation as it applies to manufactured imports. Second, advantages and disadvantages of the ROO schemes as implemented by the United States are also discussed. Third, the report illustrates ways in which the application of the rules of origin system can lead to country of origin determinations that could be inconsistent with U.S. policy objectives or goals, or encourage businesses to circumvent them. The report concludes with some options that Congress could consider in order to improve the ROO process

Report of the Fourth District Economists' Roundtable

A summary of the 1994 forecasts for real output and inflation presented by 15 members of the Fourth District Economists' Roundtable at their January 1994 meeting, highlighting the measurement of service sector prices and the role of small businesses in creating jobs.Federal Reserve District, 4th

Midyear report of the Fourth District Economists' Roundtable

A summation of the May 20, 1994 meeting of the Fourth District Economists' Roundtable, at which participants offered their views on the current and prospective state of the economy and discussed the limitations of describing the U.S. business cycle.Federal Reserve District, 4th

The regulation and structure of nonlife insurance in the United States

The insurance industry is underdeveloped in most developing countries because of low levels of income and wealth and because restrictive regulations inhibit the supply of insurance services. But several countries have begun to reform their insurance industries. To help those countries, the authors offer an overview of insurance regulation in the United States - and discuss the economics and market structure of nonlife insurance in entry and exit barriers, economies of scale, and conduct and performance studies. They conclude that the U.S. nonlife insurance industry exhibits low concentration at both national and state market levels. Concentration is low even on a line-by-line basis. The primary concern of regulators has been to protect policyholders from insolvency, but regulation has also often been used to protect the market position of local insurance companies against the entry of out-of-state competitors. Regulation has worked best when based on solvency monitoring, with limited restrictions on entry. It has been more harmful when it involved controls on premiums and products and on the industry's level of profitability. Over the years the industry has shown a remarkable degree of innovation, although it has also faced many serious and persistent problems. The problems include the widespread crisis in liability (including product liability and medical malpractice), the crisis in automobile insurance, the volatility of investment income, the effects of market-driven pricing and underwriting cycles, and the difficulty of measuring insurance solvency. The long-tailed lines of insurance - those that entail long delays in final settlements - are exposed to the vagaries of inflation and rising costs. Two mandatory lines - third party automobile insurance and workers'compensation (for work accidents) - account for nearly 55 percent of premiums. These two lines - plus medical malpractice, other liability, and aircraft insurance - had combined ratios well over 125 percent in 1989. The industry has some ability to collude and to set prices, but seems to be competitive and to earn profits below similarly situated financial firms. Insurance profitability is not consistently above or below normal returns, although earnings for mandatory and strictly regulated lines of automobile insurance and workers'compensation appear to be below-adequate for long-term viability.Insurance&Risk Mitigation,Non Bank Financial Institutions,Insurance Law,Environmental Economics&Policies,Financial Intermediation

Year-end report of the Fourth District Economists' Roundtable

A review of the November 3, 1994 meeting of the Fourth District Economists' Roundtable, at which participants offered their economic predictions for the coming year and discussed the interactions between seasonal cycles and business cycles.Economic conditions - United States

Realignment in the U.S. motor vehicle industry

A review of the developments that have led to chronic excess capacity in the U.S. motor vehicle industry, and a consideration of the prospects facing this industry in the decade ahead.Automobile industry and trade

Strong photon non-linearities and photonic Mott insulators

We show, that photon non-linearities in electromagnetically induced transparency can be at least one order of magnitude larger than predicted in all previous approaches. As an application we demonstrate that, in this regime they give rise to very strong photon - photon interactions which are strong enough to make an experimental realization of a photonic Mott insulator state feasible in arrays of coupled ultra high-Q micro-cavities.Comment: minor changes, to appear in Phys. Rev. Let