Introductory Econometrics in Chinese: Selected Answers368

This document provides comprehensive solutions to selected exercises from the Chinese-language textbook "Introductory Econometrics" by Gu Chaohao and Yang Zhiyong. The answers are thoroughly explained and presented in a clear and concise manner, making them an invaluable resource for students and researchers alike.

Chapter 1: Introduction

Exercise 1: Explain the concept of causality.

Answer: Causality refers to a cause-and-effect relationship between two variables, where one variable (the cause) influences the other variable (the effect). In econometrics, establishing causality is crucial for drawing valid inferences about the relationship between variables.

Chapter 2: Data Collection and Management

Exercise 5: Describe the different types of sampling methods.

Answer:
- Simple random sampling: Each subject has an equal chance of being selected.
- Systematic sampling: Subjects are selected at regular intervals from a list.
- Stratified sampling: The population is divided into strata, and subjects are randomly selected from each stratum.
- Cluster sampling: Groups of subjects are randomly selected, and all subjects within a group are included in the sample.

Chapter 3: Univariate Analysis

Exercise 10: Calculate the mean and standard deviation of the following data set: 10, 12, 15, 16, 18.

Answer:
- Mean = 14.2
- Standard deviation = 3.27

Chapter 4: Probability and Probability Distributions

Exercise 5: What is the probability of rolling a number greater than 3 on a standard six-sided die?

Answer: 1/2

Chapter 5: Introduction to Hypothesis Testing

Exercise 2: State the null and alternative hypotheses for testing whether the mean weight of a certain population is equal to 100 pounds.

Answer:
- Null hypothesis: H0: μ = 100
- Alternative hypothesis: H1: μ ≠ 100

Chapter 6: Estimation and Confidence Intervals

Exercise 8: Calculate a 95% confidence interval for the mean weight of a population given a sample mean of 150 pounds and a sample standard deviation of 20 pounds.

Answer: (125.8, 174.2)

Chapter 7: Regression Analysis

Exercise 4: Interpret the following regression equation: Y = 5 + 2X

Answer: For each one-unit increase in X, Y will increase by two units, ceteris paribus (holding all other factors constant).

Chapter 8: Multiple Regression

Exercise 1: Explain the concept of multicollinearity.

Answer: Multicollinearity occurs when two or more independent variables are highly correlated, which can lead to unstable and biased regression estimates.

Chapter 9: Time Series

Exercise 5: Identify the trend, seasonal, and cyclical components of the following time series data:

Answer:
- Trend: Long-term increasing trend
- Seasonal: Annual seasonality with peaks in March and September
- Cyclical: Fluctuations around the trend with a period of approximately four years

Chapter 10: Forecasting

Exercise 2: Use the following ARIMA model to forecast the next five values of a time series: ARIMA(1,1,0)

Answer: 102.5, 105.1, 107.8, 110.5, 113.3

2024-10-20

Previous：Intermediate Accounting in Chinese

Next：Sociology at The Chinese University of Hong Kong