According to Malthus, population increases at geometric rte whereas means of life increase at arithmetic rate. The geometric growth rate means the progression in the series, 2,4,8,16,32 and so on. It is increase in population at an exponential or increasing rater. The arithmetic growth means the progression like in the series 2,4,6,8,10,12,14 and so on. It means the means of life increases at constant rate. According to Malthus, it is because of operation of law of diminishing return. As population grows faster than means of life, the human beings have to suffer scarcity of means of life. The population becomes too explosively large in comparison to the means of life. Ultimately nature brings natural disaster to control the population. The disasters reduce the population. After disasters, population grows again at geometric rate. It becomes again explosively large and there is deficiency of means of life. After growth of population, the disasters and population growth occur alternatively one after another and recurrently. According to Malthus, population becomes double after 25 years. Human beings can do a little to control the population. He has referred to some measures like

- Abstinence form sex
- Late marriage
- Celibacy

He couldn’t refer family planning and prostitution as the effective measures to control population because these were against the social and religious values in that time. His theory can be explained with the help of table and figure as following:

TIME | POPULATION | MEANS OF LIFE ( IN TONS) |

1 | 2000 | 2000 |

2 | 4000 | 4000 |

3 | 8000 | 6000 |

4 | 16000 | 8000 |

5 | 32000 | 10000 |

In the above table population grows in geometric rate from 2000 to 4000, 8000, 16000 and 32000 in 2nd, 3rd, 4th and 5th year respectively. But means of life in increased at arithmetic rate from 2000 tons to 4000, 6000, 8000, 0000 tons respectively. If we represent the population and means of life with respect to time we obtain exponential curve and a straight line upwardly sloped.

In the above figure, the upper curve represents the population. It is exponential in shape. It shows that the population grows geometrically. The lower curve represents means of life. It is liner in shape. It shows that means of life increases arithmetically

Main propositions of Malthusian theory of population

- Population grows in geometric rate like in the series 2,4,8,16,32 and so on. It takes 25 years to double the population. Population growth is a natural phenomenon
- Means of life grows in arithmetic rate. The arithmetic growth means the progression like in the series 2,4,6,8,10,12,14 and so on. It means the means of life increases at constant rate. According to Malthus, it is because of operation of law of diminishing return.
- There are two types of checks: positive checks: When the population becomes too explosively large in comparison to the means of life, nature brings natural disaster to control the population. The disasters reduce the population. And preventive checks : Abstinence form sex, Late marriage, Celibacy
- Positive checks are inevitable.

**Criticisms of Malthusian theory**

- It is pessimistic theory. According to it, natural disasters are inevitable.
- Population growth is always not problematic
- The population may increase or decrease with time. In many countries it is increased but not in geometric rate. In some countries, population decreases too.
- It ignores the change in social, cultural, and political values. It also avoid modern family planning techniques
- Technological advancement, exploration of new resources etc can bring increase in return of production too.
- The preventive checks are difficult to adopt.