Consider the following statements regarding Peri-urban Areas:

1. Peri-urban areas are zones of dynamic land-use transition between rural and urban systems.
2. They are administratively fully integrated within municipal corporations.
3. Occupational structure in peri-urban areas reflects both agrarian and non-agrarian activities.
4. Peri-urbanization is often associated with informal housing and speculative land markets.

Which of the above statements are correct?