Gun Control and Violent Crime Relationship

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* p ** p *** p

The regression result in the first column shows the relationship between violence rate and shall law is not very significant, p-value for null hypothesis β0 =0 is larger than 0.05, accept the null hypothesis, shall-carry law has no impact on violence crime rate, adjusted R Square is not only 0.0302, which indicates that shall law can only explain extremely limited influence to violence rate. However, incarceration rate in the state in the previous year has a significant influence to violence rate at 99% significant level. Adjusted R square at column 2 is the highest and its root MSE is the lowest, which can interpret that incarceration rate is an explanatory variable for violent crime rate.

Although shall issue do not have linear regression relationship with violence crime rate, they may have non-linear regression relationship, log-linear model was taken because shall is binary variable and its linear value do not have mathematic meaning. The variable “lvio” is the log value of violence crime rate. Table 3 shows the regression result for log-linear model, as to shall, the impact is still not significant at 95% significant interval, adjusted R square is lower than linear regression model when adding other variables. Linear regression model can better explain the relationship between these variables with violence crime rate.

Table 3: Log-Linear Regression result for lvio

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

lvio

lvio

lvio

lvio

lvio

lvio

lvio

lvio

shall

-0.310

-0.249

-0.368*

-0.294

-0.271

-0.264

-0.229

-0.191

(0.160)

(0.125)

(0.139)

(0.166)

(0.167)

(0.170)

(0.164)

(0.157)

incarc_rate

0.00136**

0.00241***

0.00251***

0.00227***

0.00231***

0.00200**

0.00198**

(0.000399)

(0.000442)

(0.000459)

(0.000488)

(0.000489)

(0.000642)

(0.000610)

density

-0.282**

-0.332**

-0.267*

-0.283*

-0.261*

-0.269*

(0.0844)

(0.0959)

(0.107)

(0.107)

(0.109)

(0.109)

avginc

0.0376

0.0243

0.0167

0.0175

0.0309

(0.0363)

(0.0374)

(0.0407)

(0.0400)

(0.0430)

pop

0.0146

0.0141

0.0142

0.00970

(0.0112)

(0.0103)

(0.0102)

(0.00910)

pm1029

-0.0531

-0.0410

-0.00934

(0.0857)

(0.0827)

(0.0801)

pw1064

-0.00942

-0.0736

(0.0135)

(0.0441)

pb1064

-0.134

(0.0948)

_cons

6.144***

5.568***

5.316***

4.633***

4.834***

5.702***

6.203**

10.38**