Placebo Test Results-Average Treatment Effects on the Treated (ATT) for Columbia
| Outcome: Change in Land Cover Proportion, 2001–2006 | Treatment: Transactions from Farmers to Nonresidents, 2006–2010a | |||
|---|---|---|---|---|
| Estimatora | OLS coefficient | Regression Adjustment with Matched Sample (n=4, Caliper=0.01) | Regression Adjustment with Matched Sample (n=5, Caliper=0.01) | Regression Adjustment with Matched Sample (n=6, Caliper=0.01) |
| ATT on Agb change | 0.0169* | 0.0159 | 0.0145 | 0.0140 |
| (0.0087) | (0.0146) | (0.0151) | (0.0151) | |
| ATT on hay change | −0.0195** | −0.0196 | −0.0183 | −0.0178 |
| (.0083) | (0.0136) | (0.0140) | (0.0140) | |
| ATT on mismatch change | −0.0142** | −0.0141 | −0.0127 | −0.0127 |
| (0.0063) | (0.0090) | (0.0094) | (0.0093) | |
| PS-test (B/R) | — | 37.5/0.89 | 30.3/0.94 | 30.5/0.85 |
| N treated: on support (all) | 47 | 44 (47) | 44 (47) | 44 (47) |
| N control: matched (all) | 609 | 142 (609) | 167 (609) | 191 (609) |
| N total | 656 | 186 (656) | 211 (656) | 235 (656) |
Note: We do not claim anticipation effects, since we do not get consistently significant placebo test results like Chabé-Ferret and Subervie (2013). Robust standard errors in parentheses.
↵a Control = farmer owner throughout the whole period; we employ propensity matching with the caliper set to 0.01. To implement the common support condition, we exclude three observations in the treatment group, which do not satisfy that each treated has at least six nearest neighbors in the control group within the radius 0.01. We carry out regression adjustment with radius matched samples on different number of near neighbors (N = 4,5,6). All matching estimators give us small insignificant trend differences in the opposite direction of the estimated effects. Even though OLS gives significant results, we do not claim anticipation effects considering the selection issue.
↵b Ag denotes agricultural land cover, except hay.
↵* p < 0.1;
↵** p < 0.05;
*** p < 0.01.