Table 2 Difference-in-differences estimation.

From: Impact of two of the world's largest protected areas on longline fishery catch rates

 

(1)

(2)

(3)

(4)

(5)

(6)

PRI expansion

0.338***

 −0.357**

 −0.591***

   
 

(0.044)

(0.162)

(0.172)

   

PMNM expansion

   

0.945***

 −0.195

 −0.489

    

(0.287)

(0.318)

(0.398)

Hawaii-based Tuna Trips

4.037***

4.169***

4.218***

1.236***

1.091***

1.980***

 

(0.044)

(0.046)

(0.093)

(0.083)

(0.086)

(0.338)

PRI * Hawaii

0.745***

0.782***

0.564***

   
 

(0.082)

(0.082)

(0.098)

   

PMNM * Hawaii

   

0.703**

0.754**

0.532

    

(0.298)

(0.303)

(0.329)

Month dummies

No

Yes

Yes

No

Yes

Yes

Year dummies

No

Yes

Yes

No

Yes

Yes

Vessel dummies

No

No

Yes

No

No

Yes

Additional controls

No

No

Yes

No

No

Yes

Observations

33,444

33,444

33,444

34,964

34,964

34,964

R2

0.160

0.177

0.222

0.022

0.043

0.092

  1. Notes: The dependent variable in all columns is Catch of Bigeye and Yellowfin Tuna per 1000 Hooks. In Columns (1)–(3), the control group is Hawaii-based swordfish trips and the sample runs from January 1st 2010 to August 25th 2016. In Columns (4)–(6), the control group is American Samoa-based tuna trips and the sample runs from January 1, 2010 to December 31, 2017. Heteroskedasticity-robust standard errors presented in parentheses. The additional controls are whether the set included an experimental component, a dummy variable for whether the WCPFC waters were closed to fishing, a dummy variable for whether IATTC waters were closed to vessels longer than 24 m, Monthly El Niño indicator, Monthly El Niño indicator lagged by 1 year, Monthly El Niño indicator lagged by 2 years, and Monthly El Niño indicator lagged by 3 years. *p < 0.1; **p < 0.05; ***p < 0.01 for two-sided t test of statistical significance using heteroskedasticity-robust standard errors.
Back to article page