Ceteris paribus is an assumption used in economic models in which the important variables that you are focusing on are kept constant.

An equilibrium is a self-perpetuating situation that does not change, even when a force for change is introduced from the outside that alters the basic data describing the situation.

An economic rent is the benefit you receive above what you would have earned from your reservation option.

In economics, a model is a simplified representation (diagrammatical or physical) that helps us to understand what is going on by focusing attention on what is important.

Malthusianism provided an explanation of why income would stay constant over centuries without trending upwards.

The predictions of Malthus were correct throughout 19th century Britain.

Malthus held that a sustained increase in income per capita would be impossible.

According to Malthusianism, the rise in productivity of labour would be offset by population growth.

Is concave.

Has diminishing average product of labour.

Has increasing returns to scale.

The average product of labour when the labour input is 2,800 is 300.

The costs of production are decreasing as the number of farmers increases.

The decreasing slopes of the rays from the origin to the production function along the curve indicate the decreasing average product of labour.

If the production function curve is an upward-sloping straight line, then there is no diminishing average product of labour.

For this production function, it is possible that initially there are economies of scale (for example, when there are two farmers instead of one, the average output increases as they efficiently share the workload).

The slopes of the rays from the origin to the production function decrease along the curve, indicating that the average product of labour is decreasing.

When the labour input is 2,800, the average product of labour is 300 kg.

If the production function curve is an upward-sloping straight line, then there is no diminishing average product of labour.