Class Notes Economies
By: blabla • June 7, 2016 • Essay • 1,351 Words (6 Pages) • 1,563 Views
Class #3
- Discrimination.
Wage = α + πMale
Where
- Wage = hourly wage earned by subjects
- Male = 1: person is a male; 0: person is a female
Table 1. Confounders (or omitted variables) that could bias estimate of π and lead to incorrect conclusions about gender discrimination:
Confounder | Sign of relation with | Sign of indirect effect (sign of b*sign of c) | If we don’t control for confounder, then π will be? | |
Wage | Gender (male) | |||
[a] | [b] | [c] | [d] | [e] |
/a/ Name of omitted variable
/b-c/ Put a + or a – sign under the column to indicate the hypothesize correlation between the omitted variable an either wage or gender.
/d/ This should include the product of the sign you put under columns b and c
/e/ If the overall indirect effect is +, then /e/ will be smaller; if the overall indirect effect is -, then /e/ will be larger.
Tasks:
- Fill in the table with the three most important confounders you think matter
- What important confounders did you exclude?
- Could you possibly control for all confounders? Why? Explain
Table 2: Gender discrimination in returns to human capital. Outcome is natural log of monetary earnings from sale of goods + wage labor, among Tsimane’ Indians, Bolivian Amazon, ≥16 years of age: Panel data 2002-2010. Multivariate regressions are OLS with robust standard errors and clustering by subject
Explanatory variables (X)s: | Outcome variable: natural logarithm of monetary earnings in previous two weeks | ||||||||
[a] | [b] | [c] | [d] | [e] | [f] | [g] | [h] | [i] | |
Male | 1.80 | 1.78 | 1.45 | 1.30 | 1.10 | 1.02 | 1.02 | 1.02 | 1.57 |
Confounders or controls intentionally included? (yes, no) | |||||||||
Education | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Height | No | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
Spanish | No | No | No | Yes | Yes | Yes | Yes | Yes | Yes |
Alcohol | No | No | No | No | Yes | Yes | Yes | Yes | Yes |
Age | No | No | No | No | No | Yes | Yes | Yes | Yes |
Experience | No | No | No | No | No | No | Yes | Yes | Yes |
Spanish | No | No | No | No | No | No | No | Yes | Yes |
Survey year | No | No | No | No | No | No | No | Yes | Yes |
Community FE* | No | No | No | No | No | No | No | No | Yes |
Share of variation explained by all the X’s in any one column: | |||||||||
R squared | 0.143 | 0.149 | 0.151 | 0.170 | 0.163 | 0.166 | 0.166 | 0.173 | 0.239 |
Male = 1: person is a male; 0: person is a female
Education=maximum years of education completed
Height = standing height in cm
Math=score 0-4 with 1 point for each of the four basic arithmetic operations
Writing and literacy coded as: 0=can’t, 1=with difficulty, 2=well
Alcohol: # of times person consumed alcohol in last week
Spanish: 0=no ability, 1=some ability, 2=fluent
[*] Community fixed effect [FE] = all variables at the community level that remain fixed during the study period (e.g., distance, altitude, # of schools)
Tasks:
- What is the male/female earnings differential without controlling for any variables? [Hint: The x, ‘male’, is a raw or linear variable]
- Is the gap large? Explain
- How much of the earnings variation is explained by gender?
- Why is the estimate unconvincing?
- What is the median differential in earnings based on the range of estimates in the table?
- Based on the first three control variables (education, height, Spanish), does the trend in the male/female earnings gap conform to what you might have expected? Explain making explicit reference to indirect effects.
- What is the female/male earnings differential if one controlled only for education, Spanish, and age?
- Compared to the estimate in column [a],
- How much of the variation in earnings can be explained by all the explanatory variables in column [i]? [Hint: comment on levels and on changes in the share of variation that is explained]
- What explains the large difference in the share of the variation explained by the Xs of column [a] vs column [i]?
- K-M argue that community attributes (e.g., good schools) matter in the accumulation of human capital and earnings. Can you find support for their thesis in the table above?
- Does the information in Table 2 support the idea that there is gender discrimination in the labor market?
- Assume that the estimates on the female/male earnings differential referred to a large organization that had multiple offices in the USA. What firm-level policies would you implement to narrow the differential? Be very specific.
Common measures. A. Coefficient of variation (CV)=SD/mean | ||||
Deviation | Square deviation | |||
Person | income | from mean | from mean | |
A | B | C=B^2 | ||
1 | 12 | -54 | 2873 | |
2 | 23 | -43 | 1815 | |
3 | 33 | -33 | 1063 | |
4 | 36 | -30 | 876 | |
5 | 52 | -14 | 185 | |
6 | 56 | -10 | 92 | |
7 | 62 | -4 | 13 | |
8 | 63 | -3 | 7 | |
9 | 85 | 19 | 376 | |
10 | 234 | 168 | 28359 | |
Total | 656 | 35658 | <=Total sum deviation from mean squared (TSDM) | |
Mean (person 1…10) | 65.6 | |||
n=# obs-1 | 9 | |||
SD=(TSDM/n)^0.5 (long hand) | 63 | |||
SD=Excel formula (=stdev(b51:b60) | 63 | |||
CV= | 0.96 |
B. Standard deviation of log (X) (not useful if X has many zeros or negative numbers). Logs normalize a distribution (Figure 1). | ||||
Person | income | Natural log | ||
1 | 12 | 2.48 | ||
2 | 23 | 3.14 | ||
3 | 33 | 3.50 | ||
4 | 36 | 3.58 | ||
5 | 52 | 3.95 | ||
6 | 56 | 4.03 | ||
7 | 62 | 4.13 | ||
8 | 63 | 4.14 | ||
9 | 85 | 4.44 | ||
10 | 234 | 5.46 | ||
SD(log income) | 0.80 |
C. Kuznets ratio: ratio of top 10(20)%/bottom 10(20)% | |||||||
Person | income | Share of total | Cumulative | Perfect equality | A=Area above B | ||
1 | 12 | 1.829% | 1.829% | 10.00% | 8.171% | <=Bottom 20% | |
2 | 23 | 3.506% | 5.335% | 20.00% | 14.665% | <=Bottom 20% | |
3 | 33 | 5.030% | 10.366% | 30.00% | 19.634% | ||
4 | 36 | 5.488% | 15.854% | 40.00% | 24.146% | ||
5 | 52 | 7.927% | 23.780% | 50.00% | 26.220% | ||
6 | 56 | 8.537% | 32.317% | 60.00% | 27.683% | ||
7 | 62 | 9.451% | 41.768% | 70.00% | 28.232% | ||
8 | 63 | 9.604% | 51.372% | 80.00% | 28.628% | <=Top 20% | |
9 | 85 | 12.957% | 64.329% | 90.00% | 25.671% | <=Top 20% | |
10 | 234 | 35.671% | 100.000% | 100.00% | 0.000% | ||
Total | 656 | 100.000% | |||||
Share of income of: | |||||||
Kuznets ratio | Bottom 20% | 5.34% | <=(5.34=1.82+3.50) | Kuznets ratio=48/5=9.6 | |||
Top 20% | 48.63% | <=(48.6=12.9+35.6) |
Examples: Sweeden=2.78; Denmark=2.86, N. Zealand=3.46, UK=4.07; Japan=4.17; USA=6.42
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