Table 2.
OLS and IV regression results: Colour Trail Tasks 1 and 2
| OLS | First-Stage IV | Reduced Form | Second-Stage IV | |||||
|---|---|---|---|---|---|---|---|---|
| (1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | |
| Dependent Variable | –ln(CTT1) | –ln(CTT2) | RetDur | RetDur | –ln(CTT1) | –ln(CTT2) | –ln(CTT1) | –ln(CTT2) |
| MarBar | –– | ––– | 4.777*** | 4.794*** | 0.00481 | 0.0100 | –– | –– |
| (5.9) | (5.9) | (0.2) | (0.6) | |||||
| RetDur | –0.00193*** | –0.00142** | ––– | –– | –– | –– | 0.0010 | 0.0021 |
| (–3.4) | (–3.2) | (0.2) | (0.6) | |||||
| Age | –0.0212*** | –0.0167*** | 0.892*** | 0.882*** | –0.0230*** | –0.0181*** | –0.024*** | –0.020*** |
| (–21.2) | (–21.6) | (29.7) | (28.9) | (–26.3) | (–26.6) | (–5.1) | (–5.6) | |
| School | 0.0111*** | 0.0134*** | –0.566*** | –0.560*** | 0.0122*** | 0.0141*** | 0.013*** | 0.015*** |
| (3.8) | (5.8) | (–5.6) | (–5.5) | (4.1) | (6.2) | (3.1) | (4.9) | |
| NoBooks | –0.0559*** | –0.0817*** | 0.458 | 0.552 | –0.0563*** | –0.0817*** | –0.057*** | –0.083*** |
| (–3.4) | (–6.4) | (0.8) | (1.0) | (–3.4) | (–6.3) | (–3.4) | (–6.3) | |
| PoorHealth | –0.0684* | –0.0476* | 0.180 | 0.113 | –0.0682* | –0.0472† | –0.068* | –0.047† |
| (–2.2) | (–2.0) | (0.2) | (0.1) | (–2.2) | (–2.0) | (–2.2) | (–1.9) | |
| PoorFam | –0.00953 | –0.0172 | 0.657 | 0.744 | –0.00990 | –0.0173 | –0.011 | –0.019 |
| (–0.4) | (–1.0) | (0.9) | (1.0) | (–0.5) | (–1.0) | (–0.5) | (–1.1) | |
| MotherNotWork | –0.00425 | –0.0156 | 1.048† | 1.160* | –0.00689 | –0.0178 | –0.0079 | –0.020 |
| (–0.3) | (–1.2) | (1.9) | (2.0) | (–0.4) | (–1.4) | (–0.5) | (–1.5) | |
| FatherNotWork | –0.0307 | –0.0224 | 0.690 | 0.736 | –0.0322 | –0.0244 | –0.033 | –0.026 |
| (–1.0) | (–0.9) | (0.7) | (0.7) | (–1.1) | (–1.0) | (–1.1) | (–1.1) | |
| Constant | –2.566*** | –3.614*** | –41.29*** | –40.87*** | –2.480*** | –3.546*** | –2.44*** | –3.46*** |
| (–33.6) | (–61.3) | (–16.4) | (–16.1) | (–33.8) | (–62.6) | (–10.8) | (–19.9) | |
| R2 (%) | 26.2 | 29.4 | 33.2 | 32.7 | 25.9 | 29.1 | –– | –– |
| N | 2,519 | 2,481 | 2,519 | 2,481 | 2,519 | 2,481 | 2,519 | 2,481 |
| First-Stage IV Statistics | ||||||||
| F statistics | –– | –– | 35.14 | 34.97 | –– | –– | –– | –– |
| Stock-Yogo Weak Identification Test critical values | ||||||||
| 10 % maximal IV size | –– | –– | 16.38 | 16.38 | –– | –– | –– | –– |
| 15 % maximal IV size | –– | –– | 8.96 | 8.96 | –– | –– | –– | –– |
| 20 % maximal IV size | –– | –– | 6.66 | 6.66 | –– | –– | –– | –– |
| 25 % maximal IV size | –– | –– | 5.53 | 5.53 | –– | –– | –– | –– |
| Hausman Test (H0: RetDur is exogenous) | ||||||||
| χ2 | –– | –– | –– | –– | –– | –– | 0.37 | 0.89 |
| p value | –– | –– | –– | –– | –– | –– | .54 | .34 |
| OLS or IV? | –– | –– | –– | –– | –– | –– | OLS | OLS |
Notes: t statistics are shown in parentheses. Abbreviations: CTT1 = Colour Trail Task 1; CTT2 = Colour Trail Task 2.
†p < .10; *p < .05; **p < .01; ***p < .001