- The analyst's advice implicitly assumes that...
Answer: the Momentum Index is a direct cause of the market downturn, rather than just a symptom of an overvalued market.
The advice to sell is based on the assumption that the indicator causes or reliably predicts the downturn. However, the indicator might simply be correlated with the actual cause. For instance, the index might reflect a period of irrational exuberance or speculative buying that leads to an overvalued market, which is the actual cause of the subsequent correction (downturn). The index is a symptom, not the disease.
- Which of the following possibilities represents a case of reverse causality that could weaken the department head's argument?
Answer: The company's advertising budget is formally set as a fixed percentage of the previous quarter's sales revenue.
Reverse causality occurs when the presumed effect is actually the cause. If the advertising budget is determined by past sales, then high sales will cause high advertising spending, rather than the other way around. This would still produce a positive correlation, but it would invalidate the conclusion that a higher budget will automatically cause higher future sales.
- An economist analyzing this situation should be cautious about concluding that the minimum wage increase caused the fall in employment primarily because...
Answer: the adoption of new technology is a confounding variable that also explains a potential decrease in the need for labor.
The key issue is the presence of a confounding variable. Two events occurred simultaneously: the minimum wage increase and the adoption of new technology. The new technology could have reduced the demand for labor independently of the wage change. Therefore, one cannot attribute the entire employment drop to the minimum wage without accounting for the effect of automation.
- An economist establishes a strong, statistically significant correlation between an increase in variable A and a decrease in variable B. To build a compelling case that an increase in A causes a decrease in B, what is the most crucial next step?
Answer: Develop a plausible economic theory and test for mechanisms that explain how A could negatively influence B.
Finding a correlation is only the first step. To establish causation, one must go beyond the statistical relationship. The most critical step is to develop a theoretical model or a plausible mechanism that explains how and why A would cause B. This involves ruling out reverse causality and confounding variables, often through more advanced statistical methods or controlled experiments, to isolate the causal pathway.
- An economist would likely challenge this conclusion by pointing to which more plausible explanation?
Answer: A major economic recession occurred during that period, simultaneously reducing household incomes (and thus savings) and increasing government borrowing for stimulus.
The politician's argument has the causality backward. A more plausible explanation is a confounding variable: an economic recession. During a recession, people's incomes fall, reducing their ability to save. At the same time, governments often increase spending (e.g., on unemployment benefits) and cut taxes to stimulate the economy, which increases government borrowing and the national debt. The recession is the third factor causing both observed phenomena.
- Which of the following policy proposals most clearly demonstrates a potential confusion of correlation with causation based on this fact?
Answer: A proposal to require all high school graduates to attend a four-year college to boost the national average income.
This proposal assumes that the act of attending college causes the higher income for everyone. It ignores confounding variables, such as innate ability, motivation, and family background, which are correlated with both college attendance and higher earnings. Forcing everyone to attend college would not grant them these other attributes, and thus would be unlikely to have the intended effect on a mass scale.
- The developer's strategy is based on a questionable assumption. What is the most likely alternative explanation for the observed data?
Answer: Coffee shops tend to open in neighborhoods where residents' incomes and property values are already rising or are expected to rise.
The developer is assuming that coffee shops cause property values to rise. It is much more likely that the causality is reversed or that a third factor is at play. Businesses, including coffee shops, choose to locate in areas where they expect to find customers with disposable income. Therefore, they are drawn to neighborhoods that are already affluent or are gentrifying (i.e., property values are already on an upward trend). The coffee shops are a symptom of rising values, not the primary cause.
- A study demonstrates a strong correlation between variable X and variable Y. A follow-up controlled experiment shows that actively intervening to increase X reliably leads to an increase in Y, while holding other factors constant. What does this experiment provide that the original study did not?
Answer: Evidence that helps to establish a causal relationship between X and Y.
The initial study only showed correlation, meaning X and Y move together. The controlled experiment, by manipulating X and observing a change in Y while holding other factors constant, provides evidence for causation. It helps rule out the possibility that a third, unobserved variable was causing both X and Y to change, which is a key step in moving from a correlational claim to a causal one.
- Which statement presents the most critical challenge to the official's conclusion about the proposed subsidy?
Answer: It is more plausible that only firms that are already highly productive have the capacity to succeed in exporting.
This is a classic case of potential reverse causality. The government official assumes that exporting causes productivity gains. However, it is more likely that high productivity is a prerequisite for a firm to be ableto compete and succeed in foreign markets. Therefore, the subsidy might not make unproductive firms more productive.
- The conclusion that being an 'admired company' causes higher stock returns is questionable primarily because...
Answer: firms that are already financially successful are more likely to be admired by the business community.
This is a potential case of reverse causality. The journal's observation suggests that a good reputation causes good financial performance. However, it is highly plausible that strong financial performance (high profits, rising stock price) is a major reason why a firm becomes admired in the first place. Success earns admiration.
- Which piece of additional information would most weaken the activist's causal claim?
Answer: Country X has a long history of political instability and weak property rights, while Country Y is known for its stable institutions.
The activist's claim is that inequality causes low growth. The information in A introduces major confounding variables. Political instability and weak property rights are widely recognized by economists as powerful inhibitors of economic growth. These factors could easily be the cause of both the low growth and the high inequality, making the observed correlation between inequality and growth spurious.
- Which statement represents the most significant potential flaw in the economist's reasoning?
Answer: Computer use is often a requirement for higher-skilled jobs that would command higher pay regardless of the tools used.
The economist is confusing correlation with causation. The observed wage premium is likely not due to the computer itself, but to the underlying skills and responsibilities of the jobs that require computer use. These are typically white-collar, higher-skilled positions. Simply giving a manual laborer a computer will not transform their job into a high-paying one. The computer is a tool associated with a type of job, not the cause of the high wage.
- Which of the following statements, if true, would most effectively counter the lobbyist's causal claim by introducing an omitted variable?
Answer: During the same period, a global recession caused a sharp decrease in the worldwide demand for steel.
The lobbyist is attributing the profit decline solely to the regulations. The existence of a global recession that reduced demand for steel is a powerful omitted variable. This global event could have caused the decline in profits, irrespective of the new regulations. This alternative explanation weakens the direct causal link the lobbyist is trying to make.
- What is the most significant flaw in the analyst's reasoning?
Answer: The analyst assumes a causal relationship where a confounding factor is a more likely explanation.
The primary flaw is confusing correlation with causation. It's likely that a third factor (a confounding variable), such as the higher tax base and wealth of residents in affluent neighborhoods, causes both the higher incomes and the greater number of public services like libraries. Building libraries is unlikely to be the cause of the income.
- Based on this correlation, which of the following is the most questionable conclusion?
Answer: Requiring all high school students to take at least five AP courses would lead to a general increase in post-college salaries.
This conclusion makes a leap from correlation to causation. It assumes that the act of taking AP classes causes higher salaries. However, a significant confounding variable is student ambition and ability. High-ability, motivated students are more likely to self-select into taking many AP courses, and these same traits are likely what lead them to secure high-paying jobs. Forcing all students to take AP classes would not grant them this underlying ambition and ability, so the policy would be unlikely to work as intended.
- What is the most significant flaw in the politician's reasoning for the proposed tax?
Answer: The politician incorrectly assumes that correlation implies causation, ignoring potential third factors.
The core error is the correlation-causation fallacy. The politician assumes watching TV causes unhappiness. It is more likely that a third variable, such as unemployment, loneliness, or poor health, could cause both an increase in television watching and a decrease in happiness. Distractor D describes reverse causality, which is possible, but A is a broader and more common critique for this type of social observation.
- An economist would most likely critique the citizens' group's conclusion by pointing out that...
Answer: the causality is likely reversed, as city officials deploy more police to areas where crime rates are already high.
The most direct and significant flaw in the group's reasoning is reverse causality. High crime rates (the effect) are likely causing an increase in police deployment (the response), not the other way around. While B is also a plausible issue, A addresses the more fundamental reason for the deployment-crime correlation.
- The consultant's recommendation is questionable primarily because it fails to consider that...
Answer: companies that were already innovative and positioned for growth were likely the first to adopt the new strategy.
This is an issue of self-selection, which is a type of omitted variable problem. The consultant assumes the strategy causes growth. However, it is very likely that the causal arrow points, at least partially, in the other direction: the characteristics that make a company likely to grow fast (e.g., innovation, good leadership) also make it more likely to adopt a new management strategy. Distractor C describes survivorship bias, which is a related but different analytical error.
- What is the most likely explanation for this statistical relationship?
Answer: Increased awareness and diagnosis of autism have occurred over the same time period that organic food has gained popularity for unrelated reasons.
This is a classic example of a spurious correlation where two variables are driven by a common trend or by separate, unrelated trends over time. Both the popularity of organic food and the rate of autism diagnosis have increased significantly in recent decades for entirely independent reasons (e.g., changing consumer preferences for food, and better diagnostic criteria/awareness for autism). There is no plausible causal link between them.
