MiscellaneousSummation notationTake the sum \(x_1+x_2+x_3+...+x_n\)We can express this sum using the summation symbol \(\Sigma\): \(\sum_{i=1}^n x_i=x_1+x_2+x_3+...+x_n\)What does the notation mean? What does the superscript mean? The subscript?IMPORTANT: Whenever I do not specify superscript and subscript, always assume \(i=1, n=n\)How do we interpret the following? \(\Sigma_{i=30}^{35}N_i\)Do example 1, p56Rules of sums & Newton's binomial formulaAdditivity property: \(\Sigma(a_i+b_i)=\Sigma a_i + \Sigma b_i\)Homogeneity property: \(\Sigma (c\cdot a_i)=c\Sigma a_i\), where \(c\) is a constantFrom the homogeneity property, it follows that \(\Sigma c=n\cdot c\). Why?Do example 2 p60: Derive the fact that the sum of the difference between \(x_i\) and its arithmetic mean \(\mu_x\) is equal to zero: \(\Sigma (x_i-\mu_x)=0\)Useful formulasGauss' formula: \(\sum i= \frac{1}{2} n(n+1)\)Proof:\(x=1+2+...+(n-1)+n\)We can rewrite this as \(x=n+(n-1)+...+2+1\)From these we can write \(2x=[n+(n-1)+...+2+1]+[1+2+...+(n-1)+n]\)Rearranging we get \(2x=(n+1)+(n-1+2)+...+(2+n-1)+(1+n)=(n+1)+(n+1)+...+(n+1)+(n+1)\)Finally, we get \(2x=n\left(n+1\right)\). Solving for \(x\): \(x=\frac{1}{2}n(n+1)\). QEDTwo other useful formulas are \(\sum i^2=\frac{1}{6}n(n+1)(2n+1)\) and \(\sum i^3=[\sum i]^2\)Newton's binomial formula: \((a+b)^m= a^m+\left( \begin{array}{c} m \\ 1 \end{array} \right)a^{m-1}b+...+\left( \begin{array}{c} m \\ m-1 \end{array} \right)ab^{m-1}+\left( \begin{array}{c} m \\ m \end{array} \right)b^m\) where the binomial coefficients \(\left( \begin{array}{c} m \\ k \end{array} \right)=\frac{m(m-1)...(m-k+1)}{k!}\) are defined for \(m=1, 2, ...\) and \(k=0,1,2,...,m\)Application of Newton's formula:\((a+b)^3=a^3+\left( \begin{array}{c} 3 \\ 1 \end{array} \right)a^{2}b+\left( \begin{array}{c} 3 \\ 2 \end{array} \right)ab^{2}+b^3\). We can use the formula from above to write \((a+b)^3=a^3+\frac{3}{1}a^{2}b+ \frac{3\cdot 2}{1\cdot 2}ab^{2}+b^3=a^3+3a^2b+3ab^2+b^3\)Double sumsIt's possible to calculate the sum of sums by using the following formula: \(\sum_{i=1}^m \sum_{j=1}^na_{ij}\)Do example 1 p65: \(\sum_{i=1}^3\sum_{j=1}^4(i+2j)=\sum_{i=1}^3[(i+2)+(i+4)+(i+6)+(i+8)]=\sum_{i=1}^3(4i+20)=(4+20)+(8+20)+(12+20)=84\)A few aspects of logicDo example 1, p66Propositions: assertions that are either true or false. When an assertion contains one or more variables for which it can be true or false we say it is an open propositionThe implication arrow: \(\Longrightarrow\)\(P\Longrightarrow Q\) you read as "p implies q" or "if p then q"The logical equivalence arrow: \( \Longleftrightarrow\)\(P \Longleftrightarrow Q\) you read as "p if and only if q"Do example 2 p67Necessary and sufficient conditions: If \(P \Longrightarrow Q\) we say that p is sufficient condition for qIf \(P\Longrightarrow Q\) we say that q is necessary condition for pExplainSolving equationsDo examples 3-4 pp68-69Mathematical proofsEvery mathematical theorem can be formulated as an implication. Indeed, all proofs of mathematical theorems rely on the establishment of implications between premises (or assumptions) and conclusions.Examples of proof methods:Direct proof: We start from the premises and we keep deriving their implications until we get to the conclusions.Indirect proof: We deny the conclusions and show that the premises must also be false. The indirect proof relies on the fact that \(P\Longrightarrow Q\) is equivalent to \(\backsim Q \Longrightarrow \backsim P\) (non-q implies non-p)Do example 1 p72Essentials of set theoryWe partially covered this last weekYou should be familiar with the following notions/notationsSet and elements: \(S= \{e_1, e_2, e_3, ..., e_n\}\)Two sets, A and B, are said to be equal if every element in A is also an element in BDo examplesProperty of a setWe can use the following notation to specify the property of a set: \(S=\{e: p\}\), where e=typical elements and p= defining propertiesExample: the budget set. \(B=\{(x, y): px+py\leq m, x\geq 0, y\geq 0\}\). Explain.Set membershipWe covered this in class last week. Remember the meaning of the following symbols:\(\subset\)\(\subseteq\)\(\in\)\(\notin\)Set operationsUnion: \(\cup \). All the elements that belong to at least one of the sets.Intersection: \(\cap\). All the elements that belong to both sets.Minus: \(\setminus\) .All the elements that belong to one set but not the other.Do example 1 p76Other important notions:Disjoint set: the empty set. For example, the intersection between two sets that do not share any membersThe universal set, \(\Omega\): The set containing all potential subsets of a family of sets.Complement set: \(A^c=\Omega\setminus A\). It contains all elements of the universal set not contained in A.

Let's \(EU=X^\alpha\) be an individual's VNM expected utility function, where \(\alpha<1\), that is to say, the individual is risk averse. The individual's income is \(W_a\) with probability \(p\) and \(W_b\) with probability \((1-p)\). The individual has access to the insurance market, where he buys \(I\) units of insurance at the price \(s\) per dollar of insurance. The individual's expected utility maximization problem isMax \(EU=p(W_a-sI)^{\alpha}+(1-p)[W_b+(1-s)I]^{\alpha}\) with respect to \(I\)The first order condition yields\(-\alpha s p (W_a-sI)^{\alpha-1}+\alpha (1-p)(1-s)[W_b+(1-s)I]^{\alpha-1}=0\)Rearranging yields\(sp(W_a-sI)^{\alpha-1}=(1-p)(1-s)[W_b+(1-s)I]^{\alpha-1}\)Exponentiating both sides of the equation by \(\frac{1}{\alpha-1}\) yields\((sp)^{1/\alpha-1}W_a-[(1-p)(1-s)]^{1/\alpha-1}W_b=[(sp)^{1/\alpha-1}+[(1-p)(1-s)]^{1/\alpha-1}]I\)Solving for the optimal value of \(I^*\) gives us the individual's demand for insurance\(I^*=\frac{(sp)^{1/\alpha-1}W_a-[(1-p)(1-s)]^{1/\alpha-1}W_b}{[(sp)^{1/\alpha-1}+[(1-p)(1-s)]^{1/\alpha-1}]}\)Note that the demand for insurance is increasing in \(W_a\) and decreasing in \(W_b\), as well as increasing with respect to the probability of the event against which the individual is insuring (this is a bit roundabout to derive, but it follows from the fact that \(\alpha<1\).

Introduction to Differential Equations.Solve the following differential Equations:1) \(\frac{dy}{dt}+y\left(t\right)\ =\ 4\ \ ;\ \ y\left(0\right)=0\)Homogeneous    \(\frac{dy}{dt}+y\left(t\right)\ =\ 0\)    \(\frac{dy}{dt}=\ -y\left(t\right)\)    \(dy\ =\ -y\left(t\right)dt\)    \(\int dy=\int -y\left(t\right)dt\)-    \(y\left(t\right)=e^{-t+c}\)    \(y(t)=e^{-t}e^c\)    \(y(t) = Ae^{-t}\)Particular    \(0+y(t) = 4\)    \(y\left(t\right)=4\)General Solution    \(y\left(t\right)=Ae^{-t}+4\)  Specific Solution    \(y\left(0\right)=Ae^{-t}+4=0\)    \(y\left(0\right)=Ae^{-\left(0\right)}=-4\)    \(y\left(0\right)=A\left(1\right)=-4\)    \(A=-4\)    \(y\left(t\right)=-4e^{-t}+4\)2) \(\frac{dy}{dt}=\ 23\ \ ;\ \ y\left(0\right)=1\)    \(dy\ =\ 23dt\)    \(\int dy\ =\ \int 23dt\)    \(y\left(t\right)\ =\ 23t+c\)specific solution

ExercisesSolve the following differential equations:1) \(\dot{y}+y=4\)\(y\left(0\right)=0\)\(\dot{y}+y=0\)\(\dot{y}=-y\)\(\frac{dy}{dt}=-y\)\(dy=-ydt\)\(-\frac{1}{y}dy=dt\)\(-\int\frac{1}{y}dy=\int dt\)\(-ln(y) +c_a = t + c_b\)                 With \(c_b - c_a = c\)\(e^{ln(y)} = e^{-t} e^c\)                                    With \(A=e^{c}\)\(y=Ae^{-t}\)\(\dot{y}=-Ae^{-t}\)Now we substitute using the conditions:\(-Ae^{-0}+0=4\)\(A=-4\)\(y=4-\dot{y}\)\(y=4+Ae^{-t}\)\(y=4+Ae^{-t}\)\(y=4-4e^{-t}\)2) \(\dot{y} =23\)\(y(0)=1\)\(\frac{dy}{dt} =23\)\(dy=23dt\)\(\int dy = 23\int dt\)

The facts of the social sciencesWho is F.A. Hayek?Hayek was a 20th century Austrian economistHe work on a variety of issues, from the theory of the trade cycle to monetary theory, from epistemology and philosophy of economics to legal theory, from political philosophy to the history of ideasHe was awarded the nobel prize in 1974 for these contributionsWhy did he write this paper and who were the targets?Starting in 1937 (Economics and Knowledge) Hayek started noticing that economics was gravitating more and more towards methodological formalism. He though this was due to the uncritical adoption of the (supposed) methodological principles of the physical sciencesThus Hayek's criticism of behaviorism, the belief that human beings respond to external stimuli in completely passive and therefore exactly predictable waysHayek adopted a sophisticated formulation of methodological dualism (later he rejected this notion thanks to the influence and Popper and shifted towards his own formulation of methodological universalism based on the notion of explanation of the principle)The methodology of the social sciencesWhat do we mean by "social sciences"?Demography vs economics, law, sociology, linguistic etc.The origins of scientific knowledge in the social sciencesThe role of introspection: We know more about human behavior thanks to the fact that we intuitively understand our fellow men than we would if we were to merely observe them as if they were atomsExample: The Marxian and the train stationOne of the most important problems in the social sciences is that of classificationIndividual things, facts, and events do not exist out thereIn the social sciences, the things are what people think they areIt's not physical properties that matter, but the relationship between objects (even non existing objects) and the mind of individual agents. As social scientists, we must impute these meanings in order to make sense of our observationsTake money: the notion of money (universally/generally accepted medium of exchange, store of value) must exist in the mind of the social scientist before he can ever identify itOf course, the human mind is fallible, thus we can make mistakeThe monology assumption: the LOGICAL structure of the human mind is the same across cultures, ethnicities, etc.Human action implies the universal notion of purposefulness (means-ends, causation, time, etc.)Praxeology as "only a kind of logic." We can derive all of the fundamental laws of economics starting from the notion of choice.Derive the law of demand.Once we have classified human behavior and the emergent results of human behavior in society (exchange, conflict) we can start to look outside the window and make sense of itThis is where timology comes in (interpretation of human events through the imputation of meaning onto the minds of the agents)What is a battle? What is a revolution? Can we observe a government?What we refer to as "historical facts" are really just theoriesSocial theory is EPISTEMOLOGICALLY and LOGICALLY prior to historical experience and therefore analysisThere is no such thing as historical analysis without theory. There is only untested and tested (logically and empirically) theoriesA theory that has been so derived can never be falso (as long as it does not contain logical inconsistencies) but merely irrelevant for the purpose at handThe economic approachWho is Gary Becker?Arguably the greatest social scientist of the second half of the 20th centuryLike Hayek, wrote on a variety of issues that were thought to be outside of the scope of economics proper (racial discrimination, the family, crime, addictive behavior, fertility, politics, and so forth)He was awarded the nobel prize in 1992Champion of "economic imperialism" and of the economic approach to human behaviorWhat is the economic approach?How to define economics?By its scope (Coase, Knight, Buchanan?): 1) Allocation of material goods; 2) the marketBy its method (Mises, Becker, Tullock)Beyond homo economicusThe three fundamental assumptions of the economic methodMaximizing behaviorMarket equilibriumFixed (given) preferencesWhat economics does not assume: perfect information, superhuman rationality, perfect foresightMaximizing behaviorThis is the same as purposeful behavior from above. People strive to achieve goals. In doing so the have to make choices.Maximization does not require rationality. But as a first approximation, we should not attribute peculiar forms of behavior to irrationalityProblem: what do we need by rationality. Instrumental vs. epistemic rationality.Instead, when we do observe peculiar behavior we should investigate further. Most likely, we ignored or failed to identify some major cost associated with the course of action we initially predictedIn fact, animals maximize too. Are animals rational?This means the same as that people respond to incentive. Is the opposite  true?Mayweather vs McgregorMarket equilibriumExtending the notion of marketsWhat do we mean by equilibriumPrices, shadow prices, and costsFixed (given) preferencesDefining preferencesNot the common meaning of the word"Underlying preferences ... over fundamental aspects of life": Health, prestige, sex, etc.Why don't individual maximize happiness?Do they maximize on "life"? Is all death suicide, in some sense?The importance of tradeoffsImplicationsThe implications of these three principles are far reachingThe law of demandThe equimarginal principleThe law of supplyImportant: economics deals with human action/choice. Everything that is outside of this realm does not belong to economics (is not to be explained by economics). It can picture into the context of economic analysis and influence the equilibrium outcome.Are the three assumptions redundant?\(\)

IntroductionGeneral informationInstructor: Ennio E. Piano, Department of Economics & F.A. Hayek Advanced Program in Politics Philosophy and Economics, George Mason UniversityEmail: [email protected] schedule: Thursday, 4:30-7:10 PM, Buchanan Hall D005Office hours: Thursday, 9:00-10:30 AM, Buchanan Hall, D137-7 (this is in the Hayek Program Office)Course structure and objectives13 lectures over three months and a halfMain goal: familiarizing yourself with the basic tools of mathematics as they are used by economists.Focus on the economics, not the mathematics. The mathematic is instrumental to the economic argument one wishes to communicate.Most of the class will cover basic calculus. If we have time we will also cover integration (unlikely). Basic calculus is what you need to know to understand most papers in economics.We will mainly look at microeconomic applications. Why? Contemporary macro is basically microeconomics "addressed in a loud voice" (Richard Wagner)Textbook: Sydsaeter et al. Essential Mathematics for Economic Analysis (any edition after the second would work, available at the bookshop on campus)Notes: The last two weeks we will review some important applications of the math learned throughout the semester, as they will be prominently features on the final exam. Plus: a good exercise to review the content of the class. I will provide my own notes with the derivation of important models.Tentative outlineSee syllabusGrading10%: Homework (two sets: #1 to be distributed on September 21st and due October 5th; #2 to be distributed on November 16th and due on November 30th). Bring a physical copy to class. Do not send me an electronic copy. I do not accept late work under ANY CIRCUMSTANCES. Also: no make up work.40%: Midterm (3-5 problems depending on difficulty)40%: Final (3-5 problems depending on difficulty, cumulative)10%: Class participation (class participation is extremely important for a class like this one. Mathematics is hard to grasp and master and requires continuous involvement (George Polya). You will be asked to come to the whiteboard and attempt to do an exercise. Everyone in the class will have to do it. You will not be graded based on whether you know the answer, but on whether you participate in the collective effort to find one.For this reason, class attendance is strongly recommended although it is not required. Why mathematical economics?Why economics?"There is only one social science..." (Gary Becker)Simple tools to explain the social worldFrom purposefulness to utility maximization to the law of demandThe theory of everythingWhy mathematics?"The objective of mathematicians is to discover and to communicate certain truths." (Daniel Solow)The "clarity argument" (e.g., Paul Romer)Good mathematical theory is valuable because it encourages clear writing and thereby produces clearer thoughts in the mind of the author. It encourages clear writing by limiting the vocabulary that the author uses. The mathematical equations depend on a limited set of symbols. In good theory, each symbol is tightly bound to specific, precisely defined word or phrase from the vocabulary. The combination of the equations and the words used in the theory give the words and symbols precise meaning. The prose in good theory does not pull in vaguely defined terms that are not in this vocabulary.Example (also from Romer)Say we want to investigate the relationship between two economic variables: human capital and knowledgeWe start with an abstract conception of the relationship:\(H\rightarrow A \rightarrow H\)

General information

General informationThursday, 4:30-7:10 PM,  Buchanan Hall (formerly, Mason Hall), D005, Fairfax campus.

General informationEnnio E. Piano, Department of Economics and F.A. Hayek Program, George Mason University,Buchanan Hall (formerly Mason Hall), [email protected] hours: Thursday, 9:00-10:30 AM or by appointment. Buchanan Hall, F.A. Hayek program office, D137-7.Course objectivesThe course is aimed at familiarizing the students with the basic tools of economic analysis, including the theory of consumer behavior, the theory of seller behavior, partial and general equilibrium theory, and game theory. The focus will be on the application of these tools to the analysis of human behavior in all its forms.PrerequisitesPrinciples of Microeconomics (ECON 103), Principles of Macroeconomics (ECON 104), and one semester of calculus (MATH 108 or 133). I expect you to be familiar with the use of algebra to solve simple sets of simultaneous equations, graphing, and to understand the concept of a derivative. ReadingsRequired textbooksHirshleifer, J., Glaezer, D., and Hirshleifer, D. 2005. Price theory and applications: Decisions, markets, and information (7th edition). Cambridge University Press.ArticlesAllen, D. W. "Property rights, transaction costs, and Coase: One more time." (https://drive.google.com/file/d/0B3CY-zqfWBQCRTlLSDltcVJ2Vzg/view?usp=sharing)Buchanan, J. M. "Cost and choice." (https://drive.google.com/file/d/0B3CY-zqfWBQCdnNXU3hOeEZzTTQ/view?usp=sharing)Cowen, T. "Public goods." (https://drive.google.com/file/d/0B3CY-zqfWBQCZjJJdWpXREc0VVk/view?usp=sharing)Shughart III, W. "Public Choice." (https://drive.google.com/file/d/0B3CY-zqfWBQCRlZpTG9DSjN1Q1U/view?usp=sharing)Staten M. and Umbeck J. "Economic inefficiency." (https://drive.google.com/file/d/0B3CY-zqfWBQCQjlzUERzQnpWRlE/view?usp=sharing)Varian, H. "How to build an economic model in your spare time." (https://drive.google.com/file/d/0B3CY-zqfWBQCMFY2dVlkYTBnMW8/view?usp=sharing)Recommended readingsAlchian, A. A., and Allen, W. R. 1969. Exchange and production: Theory in use. Wadsworth.David Friedman. Price Theory: An Intermediate Text. 1985. (Available free online: http://www.daviddfriedman.com/Academic/Price_Theory/PThy_ToC.html)Scheduled outlineAugust 28th-30thClass overview and introduction. Hirshleifer, chapter 1.September 4th-6thPreferences and choice. Hirshleifer, chapter 3; Buchanan, "Cost and choice."September 11th-13thConsumption and the derivation of the laws of demand. Hirshleifer, chapter 4. Quiz 1.September 18th-20thDemand theory, extensions. Hirshleifer, chapter 5. Quiz 2.September 25ht-27thPure exchange. Hirshleifer, chapters 2 and 14. Quiz 3.October 2nd-4thProperty rights, transaction costs, and the Coase theorem. Hirshleifer, chapter 14; Allen, D. W. "Property rights, transaction costs, and Coase: One more time." Quiz 4.October 10th-11thThe economics of time. Hirshleifer, chapter 15. Quiz 5.October 16thMidterm review.October 18thMidterm.October 23rd-25thThe theory of the firm and introduction to production theory. Hirshleifer, chapter 6.October 30th-November 1stThe theory of the competitive firm. Hirshleifer, chapter 7. Quiz 6.November 6th-8thThe theory of the monopolistic firm. Hirshleifer, chapter 8. Quiz 7.November 13th-15thIntroduction to game theory and the theory of oligopoly. Hirshleifer, chapter 10. Quiz 8.November 20th-27thWelfare economics. Hirshleifer, chapter 16; Cowen, "Public goods;" Staten and Umbeck, "Economic inefficiency." Quiz 9.November 29th-December 4thPublic choice theory and "How to build an economic model in your spare time!" Hirshleifer, chapter 17; Shughart, "Public choice." Quiz 10.December 6thFinal review.Other important datesSeptember 5th, last day to add and drop classes without penalty.September 19th, last day to drop with a 33% tuition penalty.September 29th, last day to drop with a 66% tuition penalty.November 22nd-26th, Thanksgiving recess.December 9th, last day of class.December 13th-20th, exam period.GradingYour grade in this course consists of ten weekly quizzes (30%), a midterm exam (35%), and a final exam (35%).Quizzes: Quiz questions are based on the assigned readings and lectures. This means you cannot and will not do well in this class unless you do the assigned readings and attend the lectures. The quizzes will always be taken on Wednesday. I will drop the lowest quiz grade to allow for unexpected events. No make-up quizzes are available. No exceptions. Midterm: The midterm date is October 16th. You cannot make-up the midterm under any circumstance. If you know ahead of time of some extenuating circumstance that will prevent you from taking the midterm, you must contact me ahead of time (i.e. at least 48 hours prior to the exam). In the event that you are excused from taking the midterm upon contacting me, I will shift your midterm grade towards your final (so your midterm will be worth 0% and your final 60%). If you do not contact me ahead of time and do not take the midterm, you will receive a zero. No exceptions. Final: The final exam date is to be announced. The final exam is comprehensive and you must take it on this date. If you know ahead of time of some extenuating circumstance that will prevent you from taking the final on the scheduled date, you must contact me ahead of time (i.e. at least one week prior to the exam). In the event that you are excused from taking the final on the scheduled date upon contacting me, we will arrange an alternate date. If you do not contact me ahead of time and do not take the final on the scheduled date, you will receive a zero. No exceptions.The grading scale is as follows:A+: 97-100%; A: 92-96%; A-: 88-91%; B+: 84-87%; B: 80-83%; B-: 76-79%; C: 70-75%; F:<70%.Academic integrityGeorge Mason University’s Honor Code requires all community members to maintain the highest standards of academic honesty and integrity. Cheating, plagiarism, lying, and stealing are all prohibited. Honor Code violations will be reported to the Honor Committee. Plagiarism is not accepted (statements from Macon web site: http://mason.gmu.edu/montecin/plagiarism/htm#plagiarism). The use of electronic devices is prohibited during an exam or a quiz; failure to comply with this will result in your failure of the assignment and potentially the failure of the class. Make sure to familiarize yourself with the GMU Honor Code, which is stated in the George Mason University Undergraduate Catalog.

HistoryMcguireDavisHierarchical Structure and OrganizationHierarchyNGIC 2009OMGs maintain a strong centralized leadership that implements rules regulating membership, conduct, and criminal activity. (8)OMGs are highly structured criminal organizations whose members engage in criminal activities such as violent crime, weapons trafficking, and drug trafficking. (8)Lauchs et al. 2015Each club has based its structure on the original Hell's Angels guide. (2)[OMGs] are clearly organized within a hierarchy and have a constitution with formal procedures. (25)Puppet ClubsNGIC 2009national-level OMGs maintain criminal networks of regional and local motorcycle clubs, commonly referred as "support", "puppet", or "duck" clubs, whose members conduct criminal activities in support of larger OMGs, and who are a source of new members. (8)Lauchs et al. 2015Puppet gangs are used by [OMGs] to recruit new members [...]. The same potential members then commit the crimes and/or take responsibility for the crime away from the patched members and senior management. By committing the crimes and insulating the members they prove their loyalty to the chapter and ensure their later incorporation into full membership. (30)EnforcementLauchs et al. 2015the Big 4 have elite subgroups responsible for lethal violence. (3)TaxesNGIC 2015OMGs demand monthly payments from each motorcycle club or sport bike club member in exchange for their use of support patches. Refusal to wear a support patch results in violence. (23)MembershipNGIC 2009Current law enforcement intelligence estimates that more than 20,000 validated OMG members, divided among hundreds of OMGs, reside in the United States (8)EvolutionCDOJ 2008OMGs, once perceived as groups of troublemakers and social rebels, evolved through the years into sophisticated criminal organizations. (14)Lauchs et al. 2015Why "outlaw"?  "Taking the lead in motorcycle organizations the AMA [...] outlined what it considered to be 'outlaw' clubs; that is, those that did not meet the standards or requirements for membership in the AMA [...]. These 'outlaw' clubs were not necessarily considered criminal, but were outside of the remit of the AMA and thus were not recognized as participants for organized rallies and events. (10)a proportion of these clubs were started by combatants returning from war, many of whom found themselves unable to adjust to life in the world away from the conflict. (12)returned soldiers from foreign wars were [...] still attracted not just to motorcycles but to the [OMGs] lifestyle and brotherhood. Clubs formed from former soldiers in the US and Australia after the Vietnam War. (15)Club members have [...] found it hard to find employment and often turn to petty crime for income. (2)As time passed there was a gradual shift towards serious criminal activity by the members of [OMGs] which progressed to participation in organized crime. [Although I]t is unclear when the participation in organized crime begun. [...] It is also possible that the move was a natural progression from being a violent club to recruitment of that violence for profit. (2)Barbarian activity is the original raison d'etre of [OMGs]. It is the core of the attraction for people to join [...]. If a person simply wished to participate in organized crime they would have sufficient opportunities without going through the difficult and lengthy process of obtaining membership in an [OMG]; they simply like and are attracted to barbarian behaviour. (32)Originally perceived by law enforcement as nothing more than groups of drunken brawlers they have more recently been viewed as sophisticated and organized groups of criminals. (54)On the expansion in the 1970s and the "patch over" strategy: "[Patching over] involves a larger club moving into a new location and, either through force or negotiation, taking over the territory. The result is that any smaller clubs in the area are either swallowed up by the [OMG] or disbanded. For the smaller club it produces instant recognition, reputation, and strength in numbers, whilst for the [OMG] it offers a greater network of opportunities and organizations to work with/through. This process began in the US during the 1965-75 period [...] as the larger clubs vied for power against each other. (16)NGIC 2015Motorcycle Gangs have evolved over the past 67 years from bar room brawlers to sophisticated criminals. OMGs, which were formed in the United States, over the last 50 years have spread internationally and today [...] are  a global phenomenon. The  Hells Angels in particular stands out for its international connectivity.  (22)Criminal ActivitiesDrug TraffickingCDOJ 2008According to the U.S. Drug Enforcement Administration (DEA), the HAMC began large-scale drug distribution during mid-1967, and they soon became the leading manufacturer and distributor of LDS. In recent times, members have been involved in the transportation and distribution of cocaine, ecstasy, hashish, heroin, LSD, and PCP. (15)October 2008, after 3 years of investigation by the ATF, 61 members of the Mongols are arrested in California (including the national president and chapter presidents) for, among other crimes, the trafficking of narcotics. (16)Lauchs et al. 2015the Bandidos were formed for the specific role of controlling the illicit drug trade and prostitution in Texas. (20)All jurisdictions that contain [OMGs] also identify members as key players in the drug market. (33)[OMGs] involvement in drugs began as them being couriers or methamphetamine and cannabis. (35)There have been many recent arrests of [OMGs] members in relation to methamphetamine sale and production; however, it would be  misleading to assume that they are the only providers or the rulers of the marketplace, for example in the late 1990s Southeast Asian gangs were involved in the middle- to upper-level trade in  methamphetamines (35) [OMGs] may have a competitive advantage through control of sections of the market [for narcotics]. For example, many [OMGs] operate security firms that police the doors of nightclubs and other entertainment venues. This allows them to ensure competitors do not gain entry to their lucrative drug marketplaces. (36)Barker and Human 2009The authors analyze a 631 newspaper articles (among those available on LexisNexis) mentioning one or more of the four largest North American OMGs between the years 1980 and 2005. The Angels are mentioned in 209 articles. According to their analysis, during this period, the Angels had been involved in at least ten criminal incidents in the United States (including the production and distribution of methamphetamine and the distribution of cocaine), three episodes in Canada, and three episodes in Australia. (177)NGIC 2015Methamphetamine, cocaine, and marijuana ranked respectively as the top three drugs that led to OMG arrests over the past two years. (26)Over the past several years, there has been reporting of OMG members retaining employment in various white-collar professions. (26)ViolenceCDOJ 2008[The ATF] labeled the Mongols as the most violent and dangerous OMG in the nation. (15)Lauchs et al. 2015territorial disputes are part of the original bikie psyche (31)NGIC 2015Over the past two years, larger motorcycle gangs have continued to gain or maintain control of geographic areas and have established new chapters, thereby attracting many new members. This has caused geographic clashes for dominance in overlapping gang-controlled areas. (24)ConflictCDOJ 2008[The rivalry between Mongols and HAMC] stems from years of conflict that began in the 1980s when the Mongols seized control of Southern California from the HAMC. (15)The Mongols are likely responsible for the murder of the president of the president of the San Francisco chapter of the HAMC in September 2008. (15)