I use QQ-plot on residuals in time series analysis and find the distribution is not normally distributed, but somehow thin-tail distributed:
I know that if the residuals are not a normal distribution, the model assumption does not hold and needs to transform the data to normality then fit the model. However, I searched some answers (how-to-transform-leptokurtic-distribution-to-normality) which are all related to transforming the heavy-tail distributed data to normal distribution.
My question is:
1.Can I use the light-tailed distribution to analyze data even under the normality assumption?
2.Does the heavy-tailed problem more severe than light-tailed problem?