I am currently writing on my master thesis, therefore i have to find out if a specific moment had an impact on a time series.
By just looking at the plot I would say that after the prize reached his maximum at observation 831, there was a shift in the trend... in other words i would say there is a structual break. I wanted to confirm my assumption by performing a chow test
on the first look i was very happy with the result.
p-value < 2.2e-16
which means that there is a structual break at observation 832
But then i replaced 832 with several different observation numbers and i noticed that the p-value declines if I run the chow test with lower observation numbers.
when i run the test on observation 1 there was a p-value of 0,23
pvalue at observation 200 = 0,19
pvalue at overvation 300 was 0,01
I can perform sctest on every single observation after 300 and it will always show a p-value < 0,01.
what am i doing wrong? is my formula Prize~Trend correct? (I am not that used to R or time series analysis in general)
I am very glad and grateful for your help