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The singular values and singular vectors of a compact operator $T$ can be estimated by discretizing $T$ (in a variety of ways) and then computing the singular value decomposition of a suitably scal...

The neo-Brandeis school of antitrust has suddenly emerged as a viable challenger to the reigning consumer welfare establishment. Assuming the mantle of Brandeis gives the neo-Brandeisians a historically grounded brand but also comes with some baggage. Among other things, the neo-Brandeisians need to be prepared to answer the following questions: (1) Will they follow Brandeis in seeing bigness as a curse not only in business but also in government? (2) Will they break cleanly with welfarism and adhere to a moral, social, and political theory of anti-bigness, even at the cost of efficiency? and (3) Will they commit themselves genuinely to Brandeis’s empiricism—that facts on the ground trump theories, wherever the facts may lead?

The Chicago School of antitrust is often thought to have killed off antitrust enforcement beginning in the late 1970s. In fact, although Chicago school prescriptions were significantly more laissez-faire than the structuralist school Chicago replaced, antitrust enforcement did not die under Chicago's influence. Rather, by directing antitrust to focus on technical economic analysis, Chicago contributed to the creation of a large and entrenched class of antitrust professionals—economists and lawyers—with a vested interest in preserving antitrust as a legal and regulatory enterprise. Today, Chicago School's consumer welfare standard and specific enforcement prescriptions are coming increasingly under political pressure and may be replaced or supplemented in the near term. But Chicago's redirection of antitrust toward technical economic analysis and technocratic reasoning seems likely to remain a durable legacy.

Michigan stands at a crossroads with respect to the way that electrical vehicles (“EVs”) are sold and serviced. For many decades, Michigan—like many other states—mandated that cars could be sold and serviced only through independent, franchised dealers and prohibited car manufacturers from selling or servicing directly. Historically, those laws were put in place to protect dealers from the superior bargaining power, and sometimes unfair practices, of the Big Three car companies—General Motors (“GM”), Ford, and Chrysler. With the advent of EV technology, it became clear that these decades-old restrictions on direct sales and servicing needed to be reconsidered. Tesla, the first large-scale EV company to market, made the case that direct sales and service were critical to EV market penetration and the success of its business model. From about 2014 forward, many states began to loosen their prohibitions on direct distribution to allow Tesla to operate. Michigan, however, went in the opposite direction. A 2014 amendment to the Motor Vehicle Franchise Act (“MVFA”), passed under questionable circumstances, was intended to shut the door on any possibility that Tesla could engage in direct sales or service in Michigan. While many other states were moving forward, Michigan moved back. Tesla filed a constitutional challenge to the 2014 amendment in federal court in the Western District of Michigan. The court made clear that it would allow the case to proceed to trial. In early 2020, Attorney General Nessel announced a settlement with Tesla that interpreted the State’s dealer law to permit Tesla to engage in any aspect of marketing a vehicle—opening showrooms, giving test drives, receiving trade-ins, setting up the sales transaction—so long as the actual sales transaction was orchestrated out of state. It also interpreted the Michigan statute to permit Tesla to open service centers, so long as it did so through a subsidiary. In effect, this interpretation of Michigan law allowed Tesla to sell and service its cars in Michigan, subject to jumping a few formal hurdles. By 2020, the EV sales issue was not just Tesla’s. Not only were most of the legacy car companies beginning to roll out EVs, but a host of new EV start-ups—Rivian, Lordstown, Lucid, Bollinger, Nikola, and others—were preparing to reach the market. These new EV start-ups join Tesla in arguing urgently for the need to sell and service their vehicles directly in order to achieve critical mass and insist that traditional dealer distribution will not work for their business model. Because they are similarly situated to Tesla, at present these companies can arguably take advantage of the Tesla settlement and operate in Michigan as Tesla does. Unfortunately, the car dealers’ lobby—which was behind the 2014 legislation—is unhappy with any prospect of direct sales. In the fall of 2020, the dealers pushed a bill—H.B. 6233—in the Michigan legislature to “close the Tesla loophole.” The original version of the bill, passed in committee, would have preserved the Tesla settlement, but prohibited other EV start-ups from direct sales and service. The version of the bill changed through floor amendment and that ultimately passed in the House went even further—it eviscerated the Tesla settlement and denied direct sales or service to any car company, including Tesla. Fortunately, the Senate did not take up the bill, and it died with the last legislative session. It’s time for Michigan to adopt reform legislation to bring clarity to the question of EV sales and to permit car companies to reach their customers directly.

Despite the idiosyncratic and sometimes counterproductive institutional scheme of federal antitrust enforcement created by failed Congressional design and decades of iterative experimentation, the U.S. antitrust agencies function relatively successfully most of the time. Because of this, the temptation is always to let well enough alone. There are many more pressing needs than major overhauls of the federal antitrust agencies. That said, if there is political will for reforms, there are no shortage of sensible possibilities.

Author(s): Barnett, Jonathan; Baye, Michael R; Cooper, James C; Crane, Daniel A; Elzinga, Kenneth G; Epstein, Richard; Garza, Deborah; Hazlett, Thomas W; Hurwitz, Justin Gus; Klein, Benjamin; Klick, Jonathan; Lambert, Thomas A; Lipsky, Tad; Manne, Geoffrey A; Masten, Scott E; Ohlhausen, Maureen; Rill, James; Rybnicek, Jan; Smith, Vernon L; Teece, David; Willig, Robert; Wright, Joshua D; Yun, John M

Estuarine organisms were impacted by the Deepwater Horizon oil spill which released ∼5 million barrels of crude oil into the Gulf of Mexico in the spring and summer of 2010. Crassostrea virginica, the American oyster, is a keystone species in these coastal estuaries and is routinely used for environmental monitoring purposes. However, very little is known about their cellular and molecular responses to hydrocarbon exposure. In response to the spill, a monitoring program was initiated by deploying hatchery-reared oysters at three sites along the Alabama and Mississippi coast (Grand Bay, MS, Fort Morgan, AL, and Orange Beach, AL). Oysters were deployed for 2-month periods at five different time points from May 2010 to May 2011. Gill and digestive gland tissues were harvested for gene expression analysis and determination of aliphatic and polycyclic aromatic hydrocarbon (PAH) concentrations. To facilitate identification of stress response genes that may be involved in the hydrocarbon response, a nearly complete transcriptome was assembled using Roche 454 and Illumina high-throughput sequencing from RNA samples obtained from the gill and digestive gland tissues of deployed oysters. This effort resulted in the assembly and annotation of 27,227 transcripts comprised of a large assortment of stress response genes, including members of the aryl hydrocarbon receptor (AHR) pathway, Phase I and II biotransformation enzymes, antioxidant enzymes and xenobiotic transporters. From this assembly several potential biomarkers of hydrocarbon exposure were chosen for expression profiling, including the AHR, two cytochrome P450 1A genes (CYP1A-like 1 and CYP1A-like 2), Cu/Zn superoxide dismutase (CuZnSOD), glutathione S-transferase theta (GST theta) and multidrug resistance protein 3 (MRP3). Higher expression levels of GST theta and MRP3 were observed in gill tissues from all three sites during the summer to early fall 2010 deployments. Linear regression analysis indicated a statistically significant relationship between total PAH levels in digestive gland tissue samples with CYP1A-like 2, CuZnSOD, GST theta and MRP3 induction. These observations provide evidence of a potentially conserved AHR pathway in invertebrates and yield new insight into the development of novel biomarkers for use in environmental monitoring activities.

The singular value decomposition (SVD) is a basic tool for analyzing matrices. Regarding a general matrix as defining a linear operator and choosing appropriate orthonormal bases for the domain and co-domain allows the operator to be represented as multiplication by a diagonal matrix. It is well known that the SVD extends naturally to a compact linear operator mapping one Hilbert space to another, the resulting representation is known as the singular value expansion (SVE). It is less well known that a general bounded linear operator defined on Hilbert spaces also has a singular value expansion. This SVE allows a simple analysis of a variety of questions about the operator, such as whether it defines a well-posed linear operator equation and how to regularize the equation when it is not well posed.

The recent revival of political interest in antitrust has resurfaced a longstanding debate about the role of industrial concentration and monopoly in enabling Hitler’s rise to power and the Third Reich’s wars of aggression. Proponents of stronger antitrust enforcement argue that monopolies and cartels brought the Nazis to power and warn that rising concentration in the American economy could similarly threaten democracy. Skeptics demur, observing that German big business largely opposed Hitler during the crucial years of his ascent. Drawing on business histories and archival material from the U.S. Office of Military Government’s Decartelization Branch, this Article assesses the historical record on the role of industrial concentration in facilitating Nazism. It finds compelling evidence that, while German big business principally did not support Hitler before he won the chancellorship in 1933, the extreme concentration of market power during the Weimar period enabled Hitler to seize and consolidate totalitarian power through a variety of mechanisms. Hence, the German experience with Nazism lends support to the idea that extreme concentration of economic power enables extreme concentration of political power. However, most of the conduct that created the radical economic concentration of the Weimar period would be unlawful under contemporary antitrust principles, which casts doubt on claims that a significant shift in antitrust enforcement is necessary to forestall antidemocratic forces.

The United States Occupational Safety and Health Administration (OSHA) was established to provide guidance to protect workers from hazards in the workplace. After broadly adopting extant health and safety standards, OSHA promulgated an expanded standard for regulation of asbestos. This standard provided for regulation of six named minerals and practices to be followed. Since the initial establishment of asbestos regulation by OSHA, other elongate particles have been considered for evaluation. This discussion describes the evolution of the OSHA regulations for asbestos, what they cover and how other materials might be regulated if they are found to pose a health risk.

The State of Michigan is currently defending a constitutional challenge to its automobile direct distribution prohibition. The lawsuit was brought by the automotive manufacturer Tesla, which has been denied a license to open show rooms or service centers in the state. A 2014 amendment to Michigan’s vehicle franchise statute tightened the statute’s direct distribution prohibition to make clear that even a manufacturer like Tesla that did not franchise dealers at all is prohibited from opening its own showrooms or service centers and dealing directly with consumers in the state. That law has been widely criticized by economists, consumer protection organizations like the Federal Trade Commission and Consumer Federation of America, environmental groups like the Sierra Club, and free market organizations like the Institute for Justice. In the Michigan litigation, the State is expected to rely on the assertion, frequently made by the dealers’ lobbyists, that maintaining a locally owned dealership system is beneficial to the State. Such assertions are grounded in the trope of the atomistic “mom and pop” dealer of American economic folklore — the family-owned, locally rooted dealership. This justification is increasingly a fiction. While some such dealerships may still exist, Michigan law does not require dealerships to be locally owned and operated or independent from other economic enterprises. Many are not.

Background Pulmonary contusion (PC) is a common injury associated with blunt chest trauma. Complications such as pneumonia and adult respiratory distress syndrome (ARDS) occur in up to 50% of patients with PC. The ability to predict which PC patients are at increased risk of developing complications would be of tremendous clinical utility. In this study, we test the hypothesis that a novel method that objectively measures percent PC can be used to identify patients at risk to develop ARDS after injury. Methods Patients with unilateral or bilateral PC with an admission chest computed tomographic angiogram were identified from the trauma registry. Demographic, infectious, and outcome data were collected. Percent PC was determined on admission chest computed tomography using our novel semiautomated, attenuation-defined computer-based algorithm, in which the lung was segmented with minimal manual editing. Factors contributing to the development of ARDS were identified by both univariate and multivariable logistic regression analyses. ARDS was defined as PaO2/FiO2 ratio of less than 200 with diffuse bilateral infiltrates on chest radiograph with no evidence of congestive heart failure. Results Quantifying percent PC from our objective computer-based approach proved successful. We found that a contusion size of 24% of total lung volume or greater was most significant at predicting ARDS, which occurred in 78% of these patients. Such patients also had a significantly higher incidence of pneumonia when compared with those with contusions less than 24%. The specificity of contusion size of 24% or greater was 94%, although sensitivity was 37%; positive predictive value was 78%, and negative predictive value was 72%. Conclusion We developed and describe a software-based methodology to accurately measure the size of lung contusion in patients of blunt trauma. In our analyses, contusions of 24% or greater most significantly predict the development of ARDS. Such an objective approach can identify patients with PC who are at increased risk for developing respiratory complications before they happen. Further research is needed to use this novel methodology as a means to prevent posttraumatic lung injury in patients with blunt trauma. Level of evidence Prognostic/epidemiologic study, level III; diagnostic study, level IV.

This report addresses some of the primary legal and regulatory issues related to the deployment of autonomous and connected vehicles. The authors are a team of researchers at the University of Michigan Law School. The authors’ research has been generously supported with funding from the University of Michigan Mobility Transformation Center. This research project involves three stages. The first stage involved initial research, drafting, and then dissemination of this draft report. The second stage involved a conference that was held at the University of Michigan Law School on April 15, 2016. In the third stage, based on comments received at the conference, the authors have finalized and publish this report.

Dominant Internet search engines such as Google have been accused of favoring their proprietary content and services in organic search rankings. Some commentators have proposed a “search neutrality” principle that would prohibit such favoritism and require search engines to rank results using neutral or objective criteria. Such criticisms are vulnerable to at least two important shortcomings. First, the relationship between search dominance and referral dominance is weak at best. A showing that dominant search engines distort competition in adjacent sites and services through self-referral has not been made. Second, requiring a “neutral” approach to search ranking would freeze search engines into an outdated “ten-blue-links” model and stymie search engine innovation.

The effects of antiresorptive agents (e.g., alendronate [Aln], osteoprotegerin [OPG]) on bone infection are unknown. Thus, their effects on implant-associated osteomyelitis (OM) were investigated in mice using PBS (placebo), gentamycin, and etanercept (TNFR:Fc) controls. None of the drugs affected humoral immunity, angiogenesis, or chronic infection. However, the significant (P < 0.05 vs. PBS) inhibition of cortical osteolysis and decreased draining lymph node size in Aln- and OPG-treated mice was associated with a significant (P < 0.05) increase in the incidence of high-grade infections during the establishment of OM. In contrast, the high-grade infections in TNFR:Fc-treated mice were associated with immunosuppression, as evidenced by the absence of granulomas and presence of Gram(+) biofilm in the bone marrow. Collectively, these findings indicate that although antiresorptive agents do not exacerbate chronic OM, they can increase the bacterial load during early infection by decreasing lymphatic drainage and preventing the removal of necrotic bone that harbors the bacteria.

The Supreme Court’s 1935 Humphrey’s Executor decision paved the way for the modern administrative state by holding that Congress could constitutionally limit the President’s powers to remove heads of regulatory agencies. The Court articulated a quartet of features of the Federal Trade Commission’s statutory design that ostensibly justified the Commission’s constitutional independence. It was to be non-partisan and a-political, uniquely expert, and performing quasi-legislative and quasi-judicial, rather than executive, functions. In recent years, the staying power of Humphrey’s Executor has been called into question as a matter of constitutional design. This article reconsiders Humphrey’s Executor from a different angle. At the end of a one hundred years natural experiment, the Commission bears almost no resemblance to the Progressive-technocratic vision articulated by the Court. The Commission is not politically independent, uniquely expert, or principally legislative or adjudicative. Rather, it is essentially a law enforcement agency beholden to the will of Congress. This finding has potentially important implications for agency design, constitutional doctrine and theory, and understanding of agency functioning.

A modeling study using hourly meteorological and pollution concentration data from across the coterminous United States demonstrates that urban trees remove large amounts of air pollution that consequently improve urban air quality. Pollution removal (03, PM10, NO2, SO2, CO) varied among cities with total annual air pollution removal by US urban trees estimated at 711,000 metric tons ($3.8 billion value). Pollution removal is only one of various ways that urban trees affect air quality. Integrated studies of tree effects on air pollution reveal that management of urban tree canopy cover could be a viable strategy to improve air quality and help meet clean air standards.

Santiago, Chile's semi-arid climate and urbanized environment poses a severe limitation for the establishment and maintenance of urban forests. Municipalities, or comunas, are the main stakeholders in the management of Santiago's public urban forests. A tenable hypothesis would be that as the socioeconomic level of a comuna increases, the better the condition of a comuna's urban forest. Unfortunately, there is little comprehensive information on management, public expenditure, and structure of Santiago's public and private urban forests. To examine this hypothesis, Santiago was divided into socioeconomic strata, then using air photo interpretation and stratified field sampling, urban forest structures were quantified by socioeconomic strata. In addition, interview surveys were used to determine municipal urban forest management and expenditures for different public urban forests based on socioeconomic strata. Urban forests in the high socioeconomic strata had fewer public trees, greater tree cover, tree and leaf area density, and leaf area index than lower socioeconomic strata. The percentage of total municipal budget allocated to public urban forest management was consistent among strata, but the total public urban forest budgets were greater in the high socioeconomic strata. Public urban forest structure is related to the socioeconomic strata of Santiago's different comunas.

Based on re-measurements (1999 and 2001) of randomly-distributed permanent plots within the city boundaries of Baltimore, Maryland, trees are estimated to have an annual mortality rate of 6.6% with an overall annual net change in the number of live trees of -4.2%. Tree mortality rates were significantly different based on tree size, condition, species, and Land use. Morus alba, Ailanthus altissima, and trees in small diameter classes, poor condition, or in transportation or commercial - industrial land uses exhibited relatively high mortality rates. Trees in medium- to low-density residential areas exhibited low mortality rates. The high mortality rate for A. altissima is an artifact of this species distribution among land use types (24% were in the transportation land use). Based on a new tree population projection model that incorporates Baltimore's existing tree population and annual mortality estimates, along with estimates of annual tree growth, Baltimore's urban forest is projected to decline in both number of trees and canopy area over the next century. Factors affecting urban tree mortality are discussed.

Based on field data from 10 USA cities and national urban tree cover data, it is estimated that urban trees in the coterminous USA currently store 700 million tonnes of carbon ($14,300 million value) with a gross carbon sequestration rate of 22.8 million tC/yr ($460 rnillion/year). Carbon storage within cities ranges From 1.2 million tC in New York, NY, to 19,300 tC in Jersey City, NJ. Regions with the greatest proportion of urban land are the Northeast (8.5%) and the southeast (7.1%). Urban forests in the north central, northeast, south central and southeast regions of the USA store and sequester the most carbon, with average carbon storage per hectare greatest in southeast, north central, northeast and Pacific northwest regions, respectively. The national average urban forest carbon storage density is 25.1 tC/ha, compared with 53.5 tC/ha in forest stands. These data can be used to help assess the actual and potential role of urban forests in reducing atmospheric carbon dioxide, a dominant greenhouse gas.

On November 21, 2014, 15 professors of antitrust law at leading U.S. universities submitted an amicus brief in the O'Bannon v. NCAA 9th Circuit appeal in support of the NCAA. They have an interest in the proper development of antitrust jurisprudence, and they agree that the court below misapplied the “less restrictive alternative” prong of the rule of reason inquiry for assessing the legality of restraints of trade under Section 1 of the Sherman Act, 15 U.S.C. § 1. They are concerned that the district court’s approach to the antitrust rule of reason, if affirmed, would grant undue authority to antitrust courts to regulate the details of organizational rules, and would also undermine the NCAA’s goal of amateurism in collegiate athletics, a goal that courts have recognized universally as valid and important — and in which the undersigned, as academics themselves, are deeply interested.

An analysis of trees in Douglas County, Kansas, reveals that this area has about 14,164,000 trees with tree and shrub canopy that covers 25.2 percent of the county. The most common tree species are American elm, northern hackberry, eastern redcedar, Osage-orange, and honeylocust. Trees in Douglas County currently store about 1.7 million tons of carbon (6.4 million tons CO2) valued at $124 million. In addition, these trees remove about 82,000 tons of carbon per year (300,000 tons CO2 per year valued at $5.8 million per year) and about 3,870 tons of air pollution per year ($17.7 million per year). Douglas County's trees are estimated to reduce annual residential energy costs by $2.9 million per year. The compensatory value of the trees is estimated at $6.2 billion. Loss of the current tree cover in the Wakarusa River watershed in Douglas County would increase annual flow by an average of 2.6 percent (88.9 million ft3). Information on the structure and functions of the regional forest can be used to inform forest management programs and to integrate regional forests within plans to improve environmental quality in Douglas County.

Anoplophora glabripennis Motschulsky, a wood borer native to Asia, was recently found in New York City and Chicago. In an attempt to eradicate these beetle populations, thousands of infested city trees have been removed. Field data from nine U.S. cities and national tree cover data were used to estimate the potential effects of A. glabripennis on urban resources through time. For the cities analyzed, the potential tree resources at risk to A. glabripennis attack based on host preferences, ranges from 12 to 61% of the city tree population, with an estimated value of $72 million-$2.3 billion per city. The corresponding canopy cover loss that would occur if all preferred host trees were killed ranges from 13-68%. The estimated maximum potential national urban impact of A. glabripennis is a loss of 34.9% of total canopy cover, 30.3% tree mortality (1.2 billion trees) and value loss of $669 billion.

Modeling the e!ects of increased urban tree cover on ozone concentrations (July 13}15, 1995) from Washington, DC, to central Massachusetts reveals that urban trees generally reduce ozone concentrations in cities, but tend to increase average ozone concentrations in the overall modeling domain. During the daytime, average ozone reductions in urban areas (1 ppb) were greater than the average ozone increase (0.26 ppb) for the model domain. Interactions of the e!ects of trees on meteorology, dry deposition, volatile organic compound (VOC) emissions, and anthropogenic emissions demonstrate that trees can cause changes in dry deposition and meteorology, particularly air temperatures, wind "elds, and boundary layer heights, which, in turn, a!ect ozone concentrations. Changes in urban tree species composition had no detectable e!ect on ozone concentrations. Increasing urban tree cover from 20 to 40% led to an average decrease in hourly ozone concentrations in urban areas during daylight hours of 1 ppb (2.4%) with a peak decrease of 2.4 ppb (4.1%). However, nighttime (20:00}1:00 EST) ozone concentrations increased due to reduced wind speeds and loss of NO x scavenging of ozone from increased deposition of NO x . Overall, 8-hour average ozone concentration in urban areas dropped by 0.5 ppb (1%) throughout the day. ( 2000 Elsevier Science Ltd. All rights reserved.

Acknowledgments Introduction Chapter 1. Classical Theories Adam Smith, The Wealth of Nations David Ricardo, Principles of Political Economy and Taxation John Stuart Mill, Principles of Political Economy Chapter 2. Federalism, Antifederalism, and Jacksonianism Max Farrand, Records of the Federal Convention of 1787 Agrippa, To the People Alexander Hamilton, Contintentalist Thomas Cooley, Limits to State Control of Private Business Chapter 3. Classicism, Neoclassicism, and the Sherman Act Alfred Marshall, Principles of Economics Arthur Twining Hadley, Economics: An Account of the Relations Between Private Property and Public Welfare Henry Rand Hatfield, The Chicago Trust Conference (of 1899) Chapter 4. Progressivism and the 1912 Election Theodore Roosevelt, The Trusts, the People, and the Square Deal William Howard Taft, We Must Get Back to Competition Woodrow Wilson, The Tariff and the Trusts Chapter 5. Imperfect, Monopolistic, and Workable Competition Edward Chamberlin, The Theory of Monopolistic Competition Joan Robinson, The Economics of Imperfect Competition John Maurice Clark, Toward a Concept of Workable Competition Chapter 6. The New Deal and the Institutionalists Adolf A. Berle and Gardiner C. Means, The Modern Corporation and Private Property Louis Brandeis, The Curse of Bigness Rexford Tugwell, The Industrial Discipline and the Governmental Arts Thurman Arnold, The Bottlenecks of Business Chapter 7. Antitrust After Populism Richard Hofstadter, What Happened to the Antitrust Movement? Chapter 8. Ordoliberalism and the Freiburg School Franz Bohm, Walter Eucken & Hans Grossmann-Doerth, The Ordo Manifesto of 1936 Franz Bohm, Democracy and Economic Power Chapter 9. Competition and Innovation Joseph Schumpeter, Capitalism, Socialism and Democracy Kenneth Arrow, Economic Welfare and the Allocation of Resources for Invention Chapter 10. Structuralism Joe Bain, Industrial Organization Carl Kaysen and Donald Turner, Antitrust Policy: An Economic and Legal Analysis The Neal Report (1967) Chapter 11. The Chicago School George Stigler, The Organization of Industry Aaron Director and Edward Levi, Law the Future: Trade Regulation Robert H. Bork, The Antitrust Paradox Richard A. Posner, The Chicago School of Antitrust Analysis Chapter 12. Transactions Costs Economics and the Post-Chicago Movement Oliver Williamson, Markets and Hierarchies: Analysis and Antitrust Implications F.M. Scherer, Conservative Economics and Antitrust: A Variety of Influences Herbert Hovenkamp, Post-Chicago Antitrust: A Review and Critique

An analysis of trees in the Chicago region of Illinois reveals that this area has about 157,142,000 trees with tree and shrub canopy that covers 21.0 percent of the region. The most common tree species are European buckthorn, green ash, boxelder, black cherry, and American elm. Trees in the Chicago region currently store about 16.9 million tons of carbon (61.9 million tons CO2) valued at $349 million. In addition, these trees remove about 677,000 tons of carbon per year (2.5 million tons CO2/year) ($14.0 million/year) and about 18,080 tons of air pollution per year ($137 million/year). Chicago's regional forest is estimated to reduce annual residential energy costs by $44.0 million/year. The compensatory value of the trees is estimated at $51.2 billion. Various invasive species, insects and diseases, and lack of adequate regeneration of certain species currently threaten to change the extent and composition of this forest. Information on the structure and functions of the regional forest can be used to inform forest management programs and to integrate forests into plans to improve environmental quality in the Chicago region. These findings can be used to improve and augment support for urban forest management programs and to integrate urban forests within plans to improve environmental quality in the Chicago region.