Coursera was launched in 2012 by Daphne Koller and Andrew Ng with the goal of giving life-changing learning experiences to students all around the world. In the modern day, Coursera is a worldwide online learning platform that provides anybody, anywhere with access to online courses and degrees from top institutions and corporations.

### Week 01: Model Thinking Coursera Quiz Answers

#### Quiz: Why Model? & Segregation and Peer Effects

Q1. Who developed the racial and income segregation model that we covered in section 2

Q2. Recall the standing ovation model. Suppose that for a particular show, perceptions of show quality are uniformly distributed between 0 and 100. Also suppose that individuals stand if they perceive the quality of the show to exceed 60 out of 100. Approximately what percentage of people will stand initially?

- 50%
- 0%
**40%**- 60%

Q3. Imagine that you have never been a cigarette smoker, but suddenly you begin to hang out with a group of people who smoke cigarettes frequently. After a few weeks, you become a regular smoker as well. This phenomenon is known as:

- Sorting
**Peer Effects**

Q4. What are the three main elements of an agent-based model?

**Aggregation (what happens?)**- Neighborhoods (houses)
**Agents (people)**- Demographics (race & income level)
**Behaviors (rules)**

Q5. Which model illustrates how extremists can create collective action such as an uprising, despite the fact that most group members have high thresholds for such behavior?

**Granovetter’s Model**- Index of Dissimilarity
- Schelling’s Model
- Identification Problem

Q6. While America is an incredibly diverse country, many of the places where Americans live are filled with people who think, believe, and vote like we do. A big reason for this is that we can choose the neighborhood we live in, the people who we associate with, the news outlets that we follow, etc. Which concept from class can best help us understand this phenomenon?

- Peer Effects
**Sorting**

### Week 02: Model Thinking Coursera Quiz Answers

#### Quiz: Aggregation & Decision Models

Q1. Imagine a street on which there exist two sub shops: Big Mike’s and Little John’s. Each Saturday, Big Mike’s draws an average of 500 people with a standard deviation of 20. Also on Saturdays, Little John’s draws an average of only 400 people with a standard deviation of 50. If both distributions are normal, which shop is more likely to attract more than 600 people on a given Saturday?

- Big Mike’s
**Little John’s**

Q2. In the game of life, a world begins with 4 cells in a row in the alive state, and no other cells alive. After 20 updates, what state is the world in? (In other words, which cells are alive at this point?).

- No cells are alive
**There are six live cells in three rows**- The cells blink on and off
- The same four cells are alive

Q3. Recall Wolfram’s one dimensional cellular automata model. Which of the following classes of outcomes can this model produce? (Hint: pick more than one).

**Complexity****Randomness****Periodic Orbits/ Patterns****Equilibrium**

Q4. Suppose that there exist three voters, each of whom is given three alternatives: A, B and C. There exist six possible strict preference orderings for these three alternatives: A>B>C, A>C>B, B>C>A, B>A>C, C>A>B, and C>B>A. The first voter has preferences A>B>C. The second voter has preferences B>C>A. Preferences of the third voter are unknown. How many of the six possible preference orderings, if selected by the third voter, would produce a voting cycle? (In a voting cycle, A defeats B, B defeats C, and C defeats A).

- 2
**1**- 4

Q5. Sarah is shopping for a computer. She researches different aspects of the computers for sale: screen size, processing speed, battery life, and price. All other things being equal, for which of these attributes would Sarah likely have *spatial* preferences? (For this question, please familiarize yourself with the concept of ceteris paribus*.*)

**Screen Size**- Processing Speed
- Battery Life
- Price

Q6. You want to go to a concert in Detroit, but you have only $80. The cost of driving will be $30. When you get to the concert, there’s a 40% chance you’ll be able to get a ticket for $50, and a 60% chance that tickets will cost more than $50. If it’s worth $130 to you to go to the concert, should you drive to Detroit to attend this concert? To solve, use a decision tree.

**Yes**- No

Q7. How many possible preference orderings exist for four alternatives? These orderings must satisfy transitivity. Write only*only* your final answer (Do NOT enter your calculations)

Q8. Suppose that each of 400 people is equally likely to vote “yes” or “no” in an election. What’s the size of the standard deviation for the total number of “yes” votes?

### Week 03: Model Thinking Coursera Quiz Answers

#### Quiz: Modules Thinking Electrons: Modeling People & Categorical and Linear Models

Q1. Think about all of the methods we have covered that allow us to model agents. Which of the following CAN be true? You may select more than one.

- A rational rule can include a behavioral bias.
**A simple rule can be exploited.****Rational behavior can be a simple rule.****A person can be a rational actor and altruistic.**

Q2. The State of Minnesota Veteran’s Administration is pushing for a bill to make contributions by military personnel to their retirement funds be automatic. If the bill passes, contributions will occur automatically unless the military member checks a box asking for the money in salary instead. The governor is against the bill, saying it will have no effect. What type of model is the governor most likely using?

- Behavioral Model
**Rational Model**- Rule Based Model

Q3. Imagine that you’re a contestant on a game show in which you must answer multiple-choice questions. Your current winnings are $20,000. A question comes up that will double your winnings if you answer correctly – taking you to $40,000 – or reduce your winnings to nothing if you answer incorrectly. You may do one of two things: take your $20,000 and walk away; or answer the question and end up with either $0 or $40,000. You reason that you have a 60% chance of answering the question correctly. However, you decide to walk away instead of answering. What type of bias does this choice represent?

- Hyperbolic Discounting
- Base Rate Bias
**Prospect Theory**- Status Quo Bias

Q4. Alicia is a rational actor. She’s in a market with 20 buyers and 20 sellers of corn. All of the other buyers and sellers are zero-intelligence agents.

Assume that Alicia is a buyer. If Alicia has a relatively high value, which of the following scenarios is true?

- Alicia bids higher than her true value.
**Alicia bids significantly less than her true value.**- Alicia will probably have the lowest bid among buyers.

Q5. If you are a rational person playing a “race to the bottom” game, how should you react to the addition of more people whom you know to be irrational?

**Shade your answer in the direction of a less rational response.**- Abandon the rational approach and make a random guess.
- Shade your answer a bit closer to the rational response.
- Do nothing different; there is still only one rational choice.

Q6. You have the following data on the number of dishes of ice cream that 4 people eat in a month:

Alice: 12

Baruk: 12

Carlos: 6

Daria: 14

You create two categories based on gender: Daria and Alice in one, and Carlos and Baruk in the other. You make predictions based on these categories. How much of the variation can you explain based on these categories, i.e. what’s your R-squared? Write your answer as a number between 0 and 1 to the hundredths place (like this: 0.XX). Write only your final answer

Q7. A student, Samuel, speculates that exam scores may be linearly related to hours spent studying. Samuel collects five data points, (X,Y), where X represents hours studied and Y represents exam score — Ricardo: (2,45); Janette: (4,80); Calvin: (7,95), Edith: (3,55); Joachim: (1,30). The mean score is 61. Samuel uses the equation Y=20X*Y*=20*X* to represent the data. Calculate the R-squared value of this line. Assuming that an R-squared value less than 0.4 is “poor”, a value between 0.4 and 0.8 is “fair”, and a value above 0.8 is “good”, how well does this line Y=20X represent the data?

- Good
- Fair
**Poor**- Not enough information

Q8. Let’s assume that temperature in the State of Michigan increases linearly between January and June. We’ll assign each day between January 1st and June 30th a number, such that January 1st=1, January 2nd=2…..July 1st=151. The following five data points (X,Y) were collected, where X represents the day and Y represents the temperature that day in degrees Fahrenheit: (1,5); (25,15); (46,22); (76,32); (140, 77). Which line better represents the data: Y=0.6X or Y=0.5X? In other words, which of these lines has the greater R-squared value?

- Y=0.6X
**Y=0.5X**

Q9. Larry has a multiple-variable equation that explains “points scored” in a soccer match as a linear function of passing skill, shooting skill and player compatibility. Each of these three variables is ranked on a scale from 1 to 10. As a team improves in one of these three respects, their score will increase. Let’s assume that the equation is precisely: Points Scored = 0.18(Passing Skill)+0.25(Shooting Skill)+0.12(Compatibility). MT United is a new soccer team using Larry’s model to maximize points scored. Should they focus most of their practice on passing, shooting or player compatibility?

- Passing
- Defense
**Shooting**- Compatibility

Q10. In the previous question, we assumed that points scored in a soccer match was a linear function: Points Scored = 0.18(Passing)+0.25(Shooting)+0.12(Compatibility), with each variable measured on a scale of 1 to 10. Imagine that all teams begin by using this equation. Suddenly “Team A” (passing=7; shooting=6; compatibility=6) BEATS “Team B” (passing=9; shooting=8; compatibility=7). How might this outcome be possible?

**Team A invested in a ‘New Reality’ that also focused on defensive skills. This allowed them to decrease the score differential enough to win.**- Team A had a larger value in the Big Coefficient of shooting, and therefore scored more points overall.
- Team B invested in defensive skills, making them superior both offensively and defensively.

### Week 04: Model Thinking Coursera Quiz Answers

#### Quiz: Modules Tipping Points & Economic Growth

Q1. Which of the following might be explained by a tipping point? (Hint: pick more than 1 answer)

**Residential Segregation****New home sales plummet by 60%****Power outages occur throughout the East Coast of the U.S.**- Last year there were 2 bunnies in a pen in my backyard. Now there are 40.

Q2. In a building with 70 residents, a rumor spreads through a diffusion process. At what point is the rate of diffusion greater: when 15 people have heard, or when 50 people have heard? (Hint: you can solve this with only a small amount of math)

**The rumor spreads faster when 50 people have heard.**- The rumor spreads faster when 15 people have heard.

Q3. Imagine that a virus has an R_0*R*0 of 9. What is the minimum percentage of the population that should be vaccinated in order to prevent the spread of this virus? Give your answer to one decimal point (e.g., 50.5). Include only your final answer, and do not enter anything else.

Q4. In our disease model (SIS), R_0*R*0 must be less than 1 in order to ensure that the disease will not spread throughout the population. In this model, R_0*R*0 is an example of which type of tipping point?

**Contextual Tipping Point**- Direct Tipping Point

Q5. Imagine a situation in which there exist four possible outcomes: one with probability \frac{1}{6}61, one with probability \frac{1}{3}31, and two with probability \frac{1}{4}41. Calculate the diversity index. (Please round your answer to the hundredths place, i.e. 5.55). Enter only your final answer, and do not include anything else

Q6. In order to attain long-run equilibrium in the Basic Growth Model, which of the following must be true?

- Savings rate and depreciation must be equal.
- Investment and output must be equal.
- Investment and depreciation must be equal.
**Savings rate and output must be equal.**

Q7. A country has a production function such that output equals 40 \sqrt{K}40*K* where K equals the amount of capital. If this country has 36 units of capital, what is its outpu

Q8. Note: this question requires careful thinking.

If output equals 30 \sqrt{K}30*K*, the savings rate equals 20%, and equilibrium output equals 1200, what is the depreciation rate?

- 10%
- 20%
- 5%
**15%**

Q9. If output equals 40 \sqrt{K}40*K*, the savings rate equals 10% and the depreciation rate is 20%, what is the long run equilibrium level of OUTPUT?

### Week 05: Model Thinking Coursera Quiz Answers

#### Quiz: Diversity and Innovation & Markov Processes

Q1. Larry and Susan both encode a problem as a checkerboard. Larry’s heuristic is to search to the North, South, East, and West.

Susan searches to the North, South, East, and West as well, but she also learned to search to the Northeast. Who will likely have fewer local optima? (Think carefully on this one!)

**Susan**- Larry

Q2. There exist three problem solvers, all solving the same problem. Each solver has five local optima. If we listed all of these local optima, what is the largest possible number of distinct (non-overlapping) local optima? (Hint: assume each problem solver correctly identifies the global optimum).

- 5
- 11
- 15
**13**

Q3. If you have a set of seven heuristics, how many unique pairs of two heuristics can be made out of these

Q4. What kind of equilibrium does a Markov process produce?

- No equilibrium. Chaos.
- Cycle Equilibrium: Constant cycling from different states in a predictable pattern.
- Point Equilibrium: Nothing changes and there is no movement.
**Statistical Equilibrium: Percentage of people in each ‘type’ remains constant, but there is movement of individuals.**

Q5. A local gym has 200 members. 60% of members who go to the gym one day, will go again the next day. 40% of members who don’t go to the gym one day, will go the next day. In equilibrium, how many members will be at the gym?

**100**- 50
- 75
- 150

Q6. Which of the following is evidence that your mood is NOT a Markov Process? That is, which of the following scenarios does not satisfy the assumptions of the Markov Convergence Theorem? (Assume that periods last one day).

**You’re always happy on Saturdays.**- Your mood jumps around a lot.
- Your moods resemble those of W.B. Yeats, who wrote “Being Irish, I have an abiding sense of tragedy which sustains me through temporary periods of joy.”

### Week 06: Model Thinking Coursera Quiz Answers

#### Quiz: Modules 1-10

Q1. When we look out at the world, we often only see macro level phenomena – such as unemployment, segregation, and inequality. Schelling’s segregation model teaches us that this macro level phenomena need not align in an intuitive way with what?

- linear models
- rational behavior
- micro level behavior
- peer effects

Q2. True or False:

In the standing ovation models, higher variance in show quality implies that fewer people will stand up initially.

- True
**False**- Q3. Identical twins Janelle and Jamie leave their hometown in Michigan to attend college. When they leave home, they’re the same in every way – down to their friends and their independent political beliefs. Janelle goes to Olivet College and becomes a Republican. Jamie goes to Alma College and becomes a Democrat. Which concept that we’ve studied thus far best
*best*explains how this might occur? - Spatial Choice
- Tipping Points
- Peer Effects
- Sortin

Q4. You run a company that makes seat cushions for airplanes. To fit on the plane, the cushions must be between 20 and 23 inches wide. If you adopt the Six Sigma approach to manufacturing the cushions, what should your goal be for the standard deviation of seat width?

Give a numerical answer using decimals to the hundredths place. For example, your answer should look like 0.67 or 0.32 or 0.9

Q5. In which of the following situations would someone be least likely to make a rational decision?

- Choosing which job offer to accept after completing college
**Choosing where to eat after arriving in a new city with a friend that you are trying to impress**- Buying life Insurance for yourself and your spouse
- Taking a medical school entrance exam

Q6. Your friend Stephano claims that he can predict the sales at your new ice cream store using a process that he calls “temporal temperature intuition.” Your sales for the first four days are $1000, $1100, $1600, and $1100. Stephano’s predictions for those four days were $1100, $1500, $1500, and $1300. Compute his R-squared in order to determine whether his model is GOOD or NO GOOD.

- GOOD
**NO GOOD**

Q7. Which of the following is linear?

- A graph of the function Y=X^2
*Y*=*X*2 - A graph of the function Y=X+1
*Y*=*X*+1 - World population as a function of time.

Q8. Political scientists use the diversity index to decide if an election was democratic. If the diversity index is close to one (this is a low diversity index), than some say that an election was not very democratic. Using the diversity index as a guide (with higher indices implying more democratic), which of the following two countries probably had a more democratic election?

Country 1: Three parties: A = 60%, B=30%, C = 10%

Country 2: Four parties: A = 70%, B=10%, C = 10%, D = 10%

**Country 1**- Country 2

Q9. True or False:

In order to attain long run equilibrium in the Basic Growth Model, investment must be equal to depreciation.

**True**- False

Q10. Imagine you live near a university with a popular basketball team. Every basketball game, you notice that exactly 30% of people take the bus and 70% walk. You also notice that half the people who walk to one game take the bus to the next game. What percentage of those who take the bus to one game, walk to the next game?

**This is impossible; it would be more than 100%**- 50%
- 30%
- 35%

Q11. Maurice and Abdul conduct research on heuristics for solving a particularly challenging problem. Each heuristic under study gets stuck on twelve local optima. Which of the following would be evidence that these two heuristics are diverse?

**C: Both A and B**- B: The intersection of the local optima is a set of size two.
- A: The union of their local optima is a set of size 22
- D: None of the above

Q12. Each member of a five person team has one unique idea for how to approach a problem. If ideas can be applied individually and in pairs to create approaches to the problem, how many total approaches does the team have? (Hint: think of this as recombination). Please input your answer as a whole number with no punctuation

Q13. Paul wants to decide for whom he will vote in an upcoming municipal election. Paul is primarily concerned with one attribute of the candidates: how liberal or conservative they are. He makes a plot with “very liberal” on one end and “very conservative” on the other end. He plots both candidates along this line, and then draws a dot indicating where his ideal candidate would fall on the line. Paul then decides for whom to vote based the closeness of each candidate to his ideal point along this line plot. This process is a simple use of which concept from class?

- Decision Trees
- Preference Aggregation
- Central Limit Theorem
**Spatial Choice Model**

Q14. What are the three classes of outcomes – other than equilibrium – that a model can produce?

- investment, depreciation, savings
- behavioral, rule based, rational
**complex, periodic, chaotic**- periodic, chaotic, stable

### Week 07: Model Thinking Coursera Quiz Answers

#### Quiz: Lyapunov Functions & Coordination and Culture

Q1. I drop a ball down the side of a bowl. It slides down the side, then up the other, and so on, until it eventually settles on the bottom of the bowl. Which of the following aspects of this process are Lyapunov Functions?

- Height of the ball
- Speed of the ball
- Both height and speed
**Neither height nor speed**

Q2. An externality is an action by one party that materially affects the happiness of someone who is not directly a party to the action. What is the implication of externalities in regards to Lyapunov Functions?

- Systems with externalities, in general, do not go to equilibrium.
**Where externalities exist, we need to define a new process (besides Lyapunov) through which equilibrium is reached.**- Social systems always have externalities, so Lyapunov is better used for economic – rather than social – systems.
- Externalities don’t materially affect whether – or how quickly – systems reach equilibrium.

Q3. Imagine a Lyapunov Function that has a maximum value of 200 and a minimum value of 0, and that increases by at least four if it is not at an equilibrium. In other words, K=4*K*=4. Which of the following must be true? Read each answer carefully. You may pick more than one answer.

**If the Lyapunov Function has a value of 200, then the process stops.****The process cannot take more than 50 periods to reach an equilibrium.**- The Lyapunov Function will have a value of 200 when the process stops

Q4. Daria has e-mails arrive every day in random amounts. She answers exactly four e-mails every day, unless her inbox is empty. Can you put a Lyapunov Function on this process?

- Yes
**No**

Q5. A firm has twenty offices. Employees can choose whether to wear suits or casual clothes. However, it turns out that people tend to feel more comfortable if they’re dressed like the other people in the office. What do you expect to happen?

- All of the firm’s employees dress similarly, regardless of which office they’re in.
- Within each office, people dress differently.
**Within an office, people dress similarly. Across offices, people dress differently.**

Q6. True or False:

Coordination tends to be a measurable difference – in which no one is better off not coordinating – whereas Standing Ovation tends to be more psychological – in which there may be some personal reason not to do what most others are doing.

**True**- False

Q7. Let’s assume that a Leader and a Follower meet. Four of their dimensions are measured on a scale of 1-9.

Leader: 7, 3, 2, 1

Follower: 5, 4, 2, 6.

What is the probability of interaction between the Leader and the Follower?

**25%**- 50%
- 10%
- 0%

Q8. Assume culture is determined by 3 dimensions, each with 2 possible traits:

Dimension 1: Greeting – players can wave or bow;

Dimension 2: Volume of speech – players can be loud or quiet;

Dimension 3: Leisure time – players can play soccer or hockey.

How many different cultures are possible?

**8**- 200
- Infinite
- 6

Q9. If small errors can occur in a culture that is otherwise consistent and coordinating, which model allows us to find an equilibrium where there is some heterogeneity*heterogeneity* within*within* cultures?

**Markov**- Lyaponuv
- Pure Coordination
- None of the above

Q10. Do we always coordinate on the best action?

**No**- Yes

### Week 08: Model Thinking Coursera Quiz Answers

#### Quiz: Path Dependence & Networks

Q1. In the Polya Process, what is the probability of drawing a blue ball on each of your first two draws? (Assume that you start with one blue ball and one red ball in the urn.)

- \frac{1}{2}21
**\frac{1}{3}31**- \frac{1}{4}41
- \frac{2}{3}32

Q2. In the Balancing Process, what is the probability of drawing a red ball on each of your first two draws? (Assume you start with one red ball and one blue ball in the urn.)

**\frac{1}{6}61**- \frac{1}{2}21
- \frac{1}{3}31
- \frac{1}{4}41if(typeof
- Q3. In the Polya Process, what are the odds of picking twenty red balls in a row? (Assume you start with one red ball and one blue ball in the urn.)
**\frac{1}{21}211**- \frac{1}{20}201
- Approx. \frac{1}{1,000,000}1,000,0001
- \frac{1}{4}41

Q4. What is the primary reason that the number and combination of public projects in existence might be a path dependent outcome? Please answer in one word, no perio

Q5. Using the Polya Process, you pick 10 balls from an urn. What is the diversity index of the distribution of possible outcomes? Please give a numeric answer

Q6. What is the average degree of a network with six nodes and fifteen edges? Please give a numeric answer

Q7. A train system connects Detroit to Chicago; Chicago to Minneapolis; Minneapolis to Milwaukee; and Milwaukee to Chicago. What’s the average path length between all pairs of cities?

**\frac{8}{6}68 or 1\frac{1}{3}31**- 8
- 1
- 2

Q8. What is the clustering coefficient of a family tree network that covers four generations? Assume every person marries and that each couple has exactly two children. Assume that the family tree in this question connects only spouses and mothers to their offspring.

If you’ve never seen a family tree, here is a link:

http://www.yangfamilytaichi.com/yang/tree/images/familytree.jpg

Q9. Suppose that we have a random clique network in which each person has 20 random friends and 100 clique friends. How many 2-friends does each person have?

Q10. Which of the following measures of a network might you use to capture social capital, if we take social capital to indicate something like the productive capacity of a group? You may select more than one answer.

**Clustering Coefficient****Average Path Length****Average Degree**

### Week 09: Model Thinking Coursera Quiz Answers

#### Quiz: Randomness and Random Walks & Colonel Blotto

Q1. Which one of the following examples best illustrates the “Paradox of Skill”?

- As in ‘beginner’s luck’, an unskilled novice is more likely than a skilled gambler to win a game of blackjack.
- A school talent show doesn’t cut anyone from performing. There is a wide range of skill levels participating. Therefore, the winner will be determined solely by luck.
**All the sprinters in the Olympic 100m dash are extremely skilled. However, since they are so close to each other in skill level, the winner is often determined by luck.**

Q2. A law firm has favorable outcomes in 80% of cases that go to court. They have repeated this feat for many, many years. They recruit the top talent and have some of the top lawyers in the country as partners. If we were to use the Skill vs. Luck Model to determine how much of the law firm’s success derives from skill, and how much derives from luck, would we expect the variable a*a* to be closer to 0 or to 1? The model tells us that Outcome = a*Luck + (1-a)*Skill*a*∗*Luck*+(1−*a*)∗*Skill*.

- 1
**0**- Q3. Brett runs a casino. The odds that a person wins on a single hand of blackjack are 50%. Brett has had millions of people come through his casino. One day, a pit boss tells Brett that someone has just won 20 hands of blackjack in a row. Brett concludes that due to the length of this streak, the wins cannot possibly be fair (or in other words, random). Is Brett’s reasoning correct? That is to say, is Brett correct to conclude that a person cannot possibly win 20 hands of blackjack in a row without cheating?
**No. It is possible that 20 wins in a row is random. Brett’s reasoning is not***not*correct.- Yes. Such a long streak could not possibly be random. Brett’s reasoning is correct.

Q4. Each year a small clothing company produces a new sweater design. The sales of each design have been shown to be independent random variables. Owing to changes in fashion, the company produces each design for three years. Assume that the value of the firm depends on its sales and that we can write the value at time t*t* as follows: V_t = S_t + S_{t-1} +S_{t-2}*Vt*=*St*+*St*−1+*St*−2 where S_t*St* equals sales at time t*t*. Which of the following will be true of the firm’s value? More than one may be true.

**The firm’s value one year will be correlated with it’s value in the next year.****The firm’s value in two years will be correlated with its value this year.**- The firm’s value in 2015 will share values with its value in 2012.

Q5. Imagine the following scenario: Rufus and Cornelius are running in an election for Prime Minister. Cornelius has $1,000 to spend in advertising, while Rufus only has $500.

There are 5 districts participating in this election. In order to win the election, a candidate must win 3 of 5 districts. Whichever candidate spends the most in advertising in a district will always*always* win that district.

Assume that Cornelius distributes his advertising budget equally among the 5 districts. Is it possible for Rufus to win the election?

- Yes, it is possible for Rufus to win.
**No, it is not possible for Rufus to win.**

Q6. Sasha has 80 troops allocated on 3 fronts. She has 40 on the 1st front, 40 on the 2nd front, and 0 on the 3rd front. What is the minimum*minimum* number of troops you would need to beat Sasha in this Blotto game? Assume – given that we’re looking for the minimum*minimum* – that you go second, having seen Sasha’s allocation, and that there are only two turns: Sasha’s first, then yours.

- 1
- 82
**42**- 83

Q7. Country A is at war with Country B. Country B has far fewer resources than Country A. Which of the following is a good strategy for Country B?

- Country B should try to decrease the number of fronts.
**Country B should try to increase the number of fronts.**- It is not possible for Country B to increase its probability of winning.

Q8. True or False: Any strategy can be defeated in a Blotto game.

- True
**False**

### Week 10: Model Thinking Coursera Quiz Answers

#### Quiz: Prisoners’ Dilemma and Collective Action & Mechanism Design

Q1. Which of the following are Prisoners’ Dilemma games? More than one correct answer is possible.

**Two neighboring countries decide whether to build up armies.****Two politicians decide whether to use negative advertisements against one another.**- Two people decide whether to shake or bow.

Q2. Which method for sustaining cooperation (of the seven we discussed) best explains why business partners cooperate with one another?

- Network Reciprocity
**Group Selection**- Kin Selection
- Laws

Q3. Each of six people must decide whether or not to let their cows graze in a meadow.

- The payoff to a person who doesn’t
*doesn*′*t*let her cow graze equals 0. - The payoff to a person who does
*does*let her cow graze equals 4−N4−*N*, where N*N*is the number who let their cows graze. - We want the highest possible sum of payoffs to these six people. To achieve this, exactly how many people should be allowed to let their cows graze

Q4. Which of the following might be a common pool resource problem? More than one answer is possible.

- Shoveling snow off sidewalks
**Lobster fishing****Turkey hunting**

Q5. A city manager offers ten free tulips to any resident who agrees to plant them.

The cost of planting is one unit of happiness.

The benefit of planting is 1.5N1.5*N*, where N*N* is the number of people who plant.

Given these numbers, what should the city manager do to make sure that people take her up on her offer?

- Encourage network effects.
- Punish people who don’t plant tulips by not picking up their garbage.
- Do nothing; it’s not a collective action problem.
**Pay people to plant the tulips.**

Q6. A student can either get a good score or a bad score on an exam. The probability of getting a good score on the exam is 0.8 if you study (put in effort e=1*e*=1) and 0.30 if you don’t study (put in effort e=0*e*=0). The cost of studying = 20.

A school wants to offer a scholarship of value M that will encourage students to study. Students will receive the scholarship if they get a high score on the exam. Students will get nothing if they receive a low score on the exam.

Which of the following values of M will ensure that students study? There may be more than one correct answer.

- 30
- 1
**41**- 25
**100**

Q7. If Maria is bidding in a Sealed Bid auction and she knows all of her opponents will bid their value, what should Maria bid?

Assume bids are uniformly distributed in the interval [0,1], as we did in lecture.

- She should bid more than her value (B>V
*B*>*V*) - She should bid a quarter of her value (B=\frac{V}{4}
*B*=4*V*) - She should bid her value (B=V
*B*=*V*) **She should bid half her value (B=\frac{V}{2}***B*=2*V*)

Q8. Which of the following makes the statement true? You may select more than one answer.

In a Second Price auction…

**the winner pays the second highest price.****you should bid your true value (assuming all players are rational).**- the revenue will always be less than the revenue of an ascending bid auction.
- the winner pays whatever they bid.
- you should bid half your value.

Q9. A Pivot Mechanism is used to allocate a public project. The cost of the project is 80. April values the project at 40. Baruk values it at 30 and Cortez values it at 20.

If these are the only three people who have positive value for the project, how much will April have to pay?

### Week 11: Model Thinking Coursera Quiz Answers

#### Quiz: Learning Models: Replicator Dynamics & Prediction and the Many Model Thinker

Q1. What are the two mechanisms by which replication occurs in the Replicator Dynamics model?

- Agents have some baseline tolerance for difference;

Agents move to accommodate this tolerance.

2. Agents retain some internal consistency;

Agents do what has the best payoff.

3. Agents always have an incentive to defect;

Agents do what has the best payoff.

**4. Agents do what a lot of other agents are doing;**

**Agents do what has the best payoff.**

Q2. Which of the following are fundamental components of Fisher’s Fundamental Theorem? You can pick more than one.

- Markov Processes
**Rugged Landscapes**- Prisoner’s Dilemma
**Replicator Dynamics**- Cooperation Games
**There is no cardinal**

Q3. In which situation would you choose Six Sigma (the importance of reducing variation) over Fisher’s Fundamental Theory (which encourages variance)?

- When trying to cure cancer.
**When you have found a global optima in either a single peaked landscape or a fixed but rugged landscape.**- When the landscape is dancing.
- When the landscape is rugged but you have not yet found a global maximum.

Q4. Diversity*Diversity* Prediction*Prediction* Theorem*Theorem*: If crowd diversity decreases, what must happen to the average error in order to retain the same crowd error?

**The average error must decrease as well.**- The average error must increase.
- The average error must not change.
- We cannot tell from the information provided.

Q5. There are three predictions: 45, 25, 56. The actual value is 39. What is the average diversity?

**164.67**- 289
- 42
- 145.32

Q6. In a job interview, you are asked to predict the number of ping pong balls that can fit into a yellow school bus. Which type of predictive model are you better off using?

**1 point**

**Linear Model**- Categorical Model

### Week 12: Model Thinking Coursera Quiz Answers

#### Quiz: Modules 12-21

Q1. People learn from others about which policies to support. Three policies are currently proposed: raising taxes, lowering taxes, and keeping taxes the same.

In October, 15% prefer cutting taxes, 20% prefer raising taxes, and 65% prefer keeping taxes the same.

In November, 35% prefer cutting taxes, 15% prefer raising taxes, and 50% prefer keeping taxes the same.

Darwin Charles, a political commentator, argues using replicator dynamics that this data proves that everyone will soon want tax cuts. Imagine a replicator model that supports his conclusions by giving each policy a fitness. Which of the following fitness levels supports Charles’ argument?

While calculating, round all calculations to the nearest hundredths place (i.e. if your calculator shows 0.346, round to 0.35).

- Fitness for cutting taxes = 3;

Fitness for raising taxes = 2.

2. Fitness for cutting taxes = 2;

Fitness for same taxes = 3;

Fitness for raising taxes = 1.

3. Fitness for cutting taxes = 2;

Fitness for same taxes = 2;

Fitness for raising taxes = 2.

**4. Fitness for cutting taxes = 3;**

**Fitness for same taxes = 1;**

**Fitness for raising taxes = 1.**

Q2. The City of Ann Arbor opened a new dog park. If D equals the number of dogs that are at the park, then happiness per dog at the park equals 40 – D. This holds so long as there are more than 10 dogs. If there are 10 dogs or fewer in the park, happiness per dog at the park equals 8. Any dogs not at the park have a happiness of 6 in all scenarios. Assume there are 100 dogs in Ann Arbor. If there are 18 dogs at the park, what is total happiness of the dogs in Ann Arbor?

- 777
- 666
- 888
**750**

Q5. Natalie is bidding in a second price auction. If she and her opponents are rational, what should she bid?

- She should bid the value she thinks is directly below her own.
- She should bid half her value.
- She should bid her value.
**She should bid above her valuation.**

Q6. There are three predictions: 105, 125, 190. The actual value is 145. Which of the following values is closest to the crowd (squared) error?

- 2,025
- 25
- 1,316.67
**40**- Q7. Consider an exchange economy in which each of four people brings a different good. Suppose that these people are altruistic – when someone becomes happier, everyone else also derives some happiness. Can trade in this environment create a Lyapunov Function?
**Yes**- No

Q8. True or False:

The Efficient Market Hypothesis tells us that if we apply a random walk model, it is possible to beat the market.

**False**- True

Q9. You are given the following information about a network:

It has an average path length of about 4,

An average degree of about 2.5,

And a mid-range clustering coefficient.

Which one of the following scenarios best fits this network structure?

For this question, use your reasoning rather than trying to set up each network and do all of the math.

- Airline’s flight network
- Lending network of adults (people who’ve loaned money to one another)
- Friendship network of college students
**European Union geographic network**- (nodes = countries, edges = shared boundaries)

Q10. True or False:

Tipping points means there are gradual changes in what is going to happen as events unfold.

Path dependence occurs when the likelihood of different outcomes changes drastically at a given point in time.

- True
**False**

Q12. Which of the following populations will have the greatest overall increase in fitness in the next time period?

1. Population XX

2. Population XXX

**3. Population X**

4. Population XXXX

Q13. What are the three classes of outcomes – other than equilibrium – that a model can produce?

**Complex, periodic, chaotic**- Chaotic, cyclic, periodic
- Path dependent, tipping points, chaotic
- Path dependent, phat dependent, chaotic

**Review: **

Based on our knowledge, we urge you to enroll in this course so you can pick up new skills from specialists. It will be worthwhile, we trust.