The Permanent Settlement, also known as the Zamindari System, was a revenue collection system introduced by Lord Cornwallis in 1793 in the Bengal Presidency of British India. Under this system, the East India Company granted the Zamindars (landlords) the rights to collect revenue from the peasants in exchange for a fixed annual payment to the Company. However, this system was rarely extended to other regions of India for several reasons.

Increase in Agricultural Prices:
- After 1810, there was a significant increase in agricultural prices in many regions of India. This increase in prices made the value of the harvest higher, leading to higher revenues for the Zamindars.
- However, the Permanent Settlement disallowed an increase in the State's share of revenue from the Zamindars. This meant that the State did not benefit from the increased agricultural prices.
- As a result, the State found it unfavorable to extend the Permanent Settlement to other regions where agricultural prices were rising as it would have meant losing out on potential revenue.

Influence of Ricardo's Economic Theories:
- The economic theories of David Ricardo, a prominent economist of the time, influenced the policymakers in British India.
- Ricardo's theories emphasized the importance of economic efficiency and free market principles. He argued that fixed land revenue systems, such as the Permanent Settlement, hindered economic growth and development.
- Policymakers, influenced by Ricardo's ideas, were reluctant to extend the Permanent Settlement to other regions as they believed it would impede economic progress.

State's Preference for Direct Settlement:
- The State, recognizing the limitations and drawbacks of the Permanent Settlement, found it expedient to settle directly with the ryots (peasants) in many regions.
- Direct settlements allowed the State to have greater control over revenue collection and the ability to adjust revenue shares based on changing economic conditions.
- This approach also allowed the State to bypass the intermediaries, such as the Zamindars, and establish a direct relationship with the peasants, which was often beneficial in terms of revenue collection and administration.

In summary, the Permanent Settlement was rarely extended to other regions because the increase in agricultural prices after 1810 increased the value of the harvest while the Permanent Settlement disallowed an increase in the State's share. Additionally, the influence of Ricardo's economic theories and the State's preference for direct settlements with the ryots also played a role in the limited extension of the Permanent Settlement.