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Como primer paso se obtienen los datos y se puede visualizar la gráfica de la variable identificada como PCE

## [1] "Year"     "Quarter"  "tiempo"   "DPI"      "GDP"      "PCE"      "CP"      
## [8] "DIVIDEND"
## [1] "tbl_df"     "tbl"        "data.frame"

Luego de esto se realiza una serie de tiempo con PCE y GDP que se puede visualizar en el siguiente gráfico.

Ahora evaluaremos la correlación entre estas variables, la cual podemos notar que es muy alta

## [1] 0.9991024

Por lo tanto generaremos un modelo y evaluaremos con varselect los valores de p que identificamos con 2

## AIC(n)  HQ(n)  SC(n) FPE(n) 
##      2      2      2      2

Podemos proceder a analizar el resumen de resultados de estos modelos. AMbos muestran un r2 muy alto casi de 1. Tambien podemos evidenciar la matriz de covarianza y correlación que igual muestra valores altos.

## 
## VAR Estimation Results:
## ========================= 
## Endogenous variables: GDP.ts, PCE.ts 
## Deterministic variables: const 
## Sample size: 134 
## Log Likelihood: -1208.96 
## Roots of the characteristic polynomial:
## 1.006 0.9007 0.2847 0.1399
## Call:
## VAR(y = datos1, p = 2)
## 
## 
## Estimation results for equation GDP.ts: 
## ======================================= 
## GDP.ts = GDP.ts.l1 + PCE.ts.l1 + GDP.ts.l2 + PCE.ts.l2 + const 
## 
##           Estimate Std. Error t value Pr(>|t|)    
## GDP.ts.l1  0.96042    0.11155   8.610 2.19e-14 ***
## PCE.ts.l1  0.74110    0.20287   3.653 0.000375 ***
## GDP.ts.l2 -0.07072    0.11018  -0.642 0.522110    
## PCE.ts.l2 -0.57426    0.20649  -2.781 0.006231 ** 
## const     24.30575   11.28947   2.153 0.033183 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## 
## Residual standard error: 34.35 on 129 degrees of freedom
## Multiple R-Squared: 0.9991,  Adjusted R-squared: 0.999 
## F-statistic: 3.438e+04 on 4 and 129 DF,  p-value: < 2.2e-16 
## 
## 
## Estimation results for equation PCE.ts: 
## ======================================= 
## PCE.ts = GDP.ts.l1 + PCE.ts.l1 + GDP.ts.l2 + PCE.ts.l2 + const 
## 
##           Estimate Std. Error t value Pr(>|t|)    
## GDP.ts.l1  0.05774    0.06454   0.895    0.373    
## PCE.ts.l1  1.09123    0.11737   9.297 4.71e-16 ***
## GDP.ts.l2 -0.07105    0.06375  -1.115    0.267    
## PCE.ts.l2 -0.06658    0.11947  -0.557    0.578    
## const      6.63225    6.53169   1.015    0.312    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## 
## Residual standard error: 19.87 on 129 degrees of freedom
## Multiple R-Squared: 0.9993,  Adjusted R-squared: 0.9993 
## F-statistic: 4.687e+04 on 4 and 129 DF,  p-value: < 2.2e-16 
## 
## 
## 
## Covariance matrix of residuals:
##        GDP.ts PCE.ts
## GDP.ts 1179.6  460.4
## PCE.ts  460.4  394.9
## 
## Correlation matrix of residuals:
##        GDP.ts PCE.ts
## GDP.ts 1.0000 0.6745
## PCE.ts 0.6745 1.0000

Procederemos a realizar una prueba a los residuos en donde evidenciamos que todos los p valor son menores a 0.01. por lo tanto es estacionaria y si hay cointegración evidenciando una relación a largo plazo

## Augmented Dickey-Fuller Test 
## alternative: stationary 
##  
## Type 1: no drift no trend 
##      lag    ADF p.value
## [1,]   0 -12.28    0.01
## [2,]   1  -7.60    0.01
## [3,]   2  -6.48    0.01
## [4,]   3  -5.45    0.01
## [5,]   4  -4.67    0.01
## Type 2: with drift no trend 
##      lag    ADF p.value
## [1,]   0 -12.23    0.01
## [2,]   1  -7.57    0.01
## [3,]   2  -6.45    0.01
## [4,]   3  -5.43    0.01
## [5,]   4  -4.65    0.01
## Type 3: with drift and trend 
##      lag    ADF p.value
## [1,]   0 -12.19    0.01
## [2,]   1  -7.54    0.01
## [3,]   2  -6.43    0.01
## [4,]   3  -5.41    0.01
## [5,]   4  -4.63    0.01
## ---- 
## Note: in fact, p.value = 0.01 means p.value <= 0.01
## Augmented Dickey-Fuller Test 
## alternative: stationary 
##  
## Type 1: no drift no trend 
##      lag    ADF p.value
## [1,]   0 -11.61    0.01
## [2,]   1  -6.85    0.01
## [3,]   2  -5.54    0.01
## [4,]   3  -5.08    0.01
## [5,]   4  -5.03    0.01
## Type 2: with drift no trend 
##      lag    ADF p.value
## [1,]   0 -11.57    0.01
## [2,]   1  -6.82    0.01
## [3,]   2  -5.52    0.01
## [4,]   3  -5.06    0.01
## [5,]   4  -5.02    0.01
## Type 3: with drift and trend 
##      lag    ADF p.value
## [1,]   0 -11.54    0.01
## [2,]   1  -6.80    0.01
## [3,]   2  -5.50    0.01
## [4,]   3  -5.05    0.01
## [5,]   4  -5.00    0.01
## ---- 
## Note: in fact, p.value = 0.01 means p.value <= 0.01

Con esta información se puede realizar diversas pruebas como Philips y Oularis, en esta se identifica que los residuos son estacionarios por lo que si hay cointegración.

## 
## ######################################## 
## # Phillips and Ouliaris Unit Root Test # 
## ######################################## 
## 
## Test of type Pz 
## detrending of series none 
## 
## Response GDP.ts :
## 
## Call:
## lm(formula = GDP.ts ~ zr - 1)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -150.279  -18.515    2.796   27.331  141.137 
## 
## Coefficients:
##          Estimate Std. Error t value Pr(>|t|)    
## zrGDP.ts  0.95334    0.03958  24.089   <2e-16 ***
## zrPCE.ts  0.08483    0.06116   1.387    0.168    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 37.23 on 133 degrees of freedom
## Multiple R-squared:  0.9999, Adjusted R-squared:  0.9999 
## F-statistic: 5.421e+05 on 2 and 133 DF,  p-value: < 2.2e-16
## 
## 
## Response PCE.ts :
## 
## Call:
## lm(formula = PCE.ts ~ zr - 1)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -104.417   -8.223    1.965   11.714   48.952 
## 
## Coefficients:
##          Estimate Std. Error t value Pr(>|t|)    
## zrGDP.ts 0.007454   0.021281    0.35    0.727    
## zrPCE.ts 0.996942   0.032886   30.32   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 20.02 on 133 degrees of freedom
## Multiple R-squared:  0.9999, Adjusted R-squared:  0.9999 
## F-statistic: 7.855e+05 on 2 and 133 DF,  p-value: < 2.2e-16
## 
## 
## 
## Value of test-statistic is: 13.4923 
## 
## Critical values of Pz are:
##                   10pct    5pct    1pct
## critical values 33.9267 40.8217 55.1911
## 
## ######################################## 
## # Phillips and Ouliaris Unit Root Test # 
## ######################################## 
## 
## Test of type Pu 
## detrending of series none 
## 
## 
## Call:
## lm(formula = z[, 1] ~ z[, -1] - 1)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -185.94  -32.81   29.65   77.98  145.10 
## 
## Coefficients:
##         Estimate Std. Error t value Pr(>|t|)    
## z[, -1]  1.54450    0.00323   478.1   <2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 81.14 on 135 degrees of freedom
## Multiple R-squared:  0.9994, Adjusted R-squared:  0.9994 
## F-statistic: 2.286e+05 on 1 and 135 DF,  p-value: < 2.2e-16
## 
## 
## Value of test-statistic is: 13.4278 
## 
## Critical values of Pu are:
##                   10pct    5pct    1pct
## critical values 20.3933 25.9711 38.3413