Here's a common misconception about log transform.

Log transform is commonly used to eliminate skewness in data.

Yet, it is not always the ideal solution for eliminating skewness.

It is important to note that log transform:
- Does not eliminate left-skewness.
- Only works for right-skewness, that too when values are small and positive.

This is evident from the image below.

It is because the log function grows faster for lower values. Thus, it stretches out the lower values more than the higher values.

In left-skewness:
- The tail exists to the left, which gets stretched out more than the majority of values that exist to the right.
- Thus, skewness isn't affected much.

In right-skewness:
- Majority of values and peak exists to the left, which gets stretched out more.
- However, the log function grows slowly when the values are large. Thus, the impact of the stretch is low.

There are a few things you can do:
- See if transformation can be avoided as it inhibits interpretability.
- If not, try box-cox transform. It is often quite effective, both for left-skewed and right-skewed data.