Central places are settlements that serve as hubs for providing goods and services to the surrounding population and areas, known as hinterlands. These central places range from small villages to large cities, each fulfilling different roles within the regional hierarchy.

Walter Christaller studied the structure of settlements in “South Germany” and put forward this theory in 1933. Being an economist, he investigated the relation between cities and the hinterland and in turn developed this empirical model. Moreover, the Central Place Theory was one of the earliest models that led to the genesis of Quantitative Revolution.

Key findings of Christaller:

• Although there is an even distribution of settlements, one can find a regular pattern in them.
• There is a relationship between the distribution, number and the size of settlements.

Based on the above findings, he propounded the “Central Place Theory”. A Central Place is the place that provides goods and services to the nearby regions. For example, the Panchayat Bhawan in the village provides the basic administrative services at the village level, so it is the central place for the village.

In Christaller’s Model, the central place is situated in the centre of the regions it serves. But it is important to note that this centre is not the geometric centre of the region; rather the central place can be located anywhere in the region.

Logically, the shape of the region is circular because the transport costs increase proportionately with distance from the centre. However, Christaller did not adopt the pure circular shape for reasons explained below.

• Threshold: The minimum population required to make a place a centre for a product or provider of services. If the population is below this limit the centre will not sustain.
• Range: The maximum distance a consumer is willing to travel to access the goods or take the services.

Stage 1: No Competitor Nearby

With no competitors nearby, the entrepreneur, aiming at profit maximization, positions themselves as far away from competitors as possible, giving the market a “circular shape” to ensure that at least one threshold value is covered. As all entrepreneurs act this way, they are evenly spaced over the plane in a “triangular lattice pattern” so they are equidistant from their six nearest competitors.

Stage 2: Competitor Appears Nearby

If there are many competitors, each with a circular market area and located at an equal distance from his six nearest neighbours, some area will remain unserved. In order to serve the unserved customers, suppliers come closer together causing the circular areas to overlap. Customers in the overlap zone will visit the nearest centre, resulting in hexagonal market areas. Higher-order centres have bigger hexagonal market areas; lower-order centres have smaller ones. This produces a mesh of hexagonal market areas where the hierarchy of central places is functionally and spatially organized.

Stage 3: Emergence of Higher Order Central Place

In an attempt to avoid overlap and to match the densest distribution of settlement points, the circular regions were converted into hexagons. A Central Place of Higher Order will provide goods and services of much longer range and this longer range will include small regions having central places of lower order. This overlapping creates a mesh of superimposed hexagons.

1. The region under consideration is flat and featureless, with no physical barriers or irregularities that would influence settlement patterns.
2. There is a uniform distribution of population across the region. People are evenly dispersed and have similar purchasing power and demand for goods and services.
3. The theory assumes a uniform and isotropic transportation network, where all areas are equally accessible and transportation costs are consistent across the region.
4. It assumes that consumers have homogeneous preferences and demand for goods and services. There are no variations in consumer behavior or purchasing power across different areas.
5. The theory assumes that economic agents, such as producers and consumers, behave rationally and aim to maximize their utility or profit. This implies that they will make location decisions based on factors such as transportation costs and market accessibility.

These assumptions allow Christaller to develop a simplified and systematic model of central place hierarchy and spatial organization within a region. However, these assumptions are idealized and may not fully reflect the complexities of real-world spatial systems.

The Centrality of a place refers to the degree/extent to which a town serves its surrounding area and can only be measured in terms of goods and services offered. There are different orders of goods and services. Some goods and services are costly and rarely purchased (like Cars/TV) and will need a large population to sustain them. Whereas, others are everyday need items and will require a small population for survival (Like Bread, Tea). The variety and quantity of goods and services it provides for its population in the region defines the Centrality of the Central Place.

The Complementary area is the area for which the central place is the focal point. This area would be larger for bigger and more important central places and smaller for the less important ones. In an isotropic surface, the complementary area is always a circle with the central place at the centre of this circle.

Threshold population is the minimum number of people required to support any good or service outlet established at a central place. It is the minimum population required for the sale of a good or to sustain any service. Some goods and services need a large population and others a small population to achieve their threshold values. For example, a grocery shop needs a relatively small local population while a car (irregularly purchased) needs a larger threshold population.

Range is the maximum distance that a consumer is willing to travel to avail the functions offered at the Central Place. For example: You can travel to a metro city to purchase an iPhone. To get critical health services, you may travel far distances like AIIMS Delhi etc.

Under the marketing principle, an urban settlement reveals consumer demand. Each consumer would try to be as close as possible to every level of the hierarchy so as to minimize travelling. Thus, a settlement of every order would be surrounded by six other settlements of the next order.

The low-order centres position themselves on the boundaries of market areas of middle-order centres. People at a lower-order centre will have a choice between three higher-order centres since all three are equidistant. Each higher-order centre then receives one-third of the customers of six immediately lower-order centres. It serves a population equivalent to two lower-order centres (6×1/3), besides its own population. Therefore, overall it serves a total of three central places (6×1/3=2+1=3).

For each one of the largest settlements there would be three of the second grade, nine of the third grade, twenty-seven of the fourth grade and so on. Thus, there is only one centre of the highest order and the number of centres at every level below it increases by a factor of three.

The transport principle states that the distribution of central places is most favorable when as many places of concern or importance lie on one traffic route between two important towns, the route being established as straight and as cheap as possible.

Central places would thus be lined up on straight traffic routes which radiate out from a central point. Lower-order centres lie along the straight-line paths between higher-order centres.

In the transport principle, a lower-order centre is equidistant from two higher-order centres (6×1/2) plus its own (1) making a total of four. When central places are arranged according to the transport principle, the lower-order centres are located at the midpoint of each side of the hexagon rather than at the corner. Thus, the transport principle produces a hierarchy organised in a K=4 arrangement. The number of settlements serving as central places at each decreasing level in the hierarchy would be 1, 4, 16, 64, 256… and so on.

The market areas of each of the higher-order centres include the entire market area of each of the six neighbouring lower-order centres. This is because law and administration in theory do not experience exponential decay with distance but remain fully enforced up to the boundaries of the administrative units in which they are applied.

For the administrative principle the numerical progression would be 1, 7, 49, 343… and so on.

Central Place Theory has been applied in a variety of fields, including urban planning, retail location analysis, and economic geography. The theory provides valuable insights into the spatial organization of settlements and can help to inform planning decisions related to the location and distribution of goods and services.

For example, Central Place Theory can be used to analyze the location of retail businesses, such as supermarkets and shopping malls. By understanding the threshold population required to support different types of retail businesses, planners can identify the optimal locations for these businesses and minimize competition between them.

CPT is normative in character and so limited in empirical applicability. No real-world settlement system can be expected to conform to all the propositions of the Central Place Theory.

India’s hierarchy system is represented from the point of view of administration and demography. India has six-level hierarchies of settlements at the administrative level. At the top of the hierarchy is the national capital followed by state capitals, district headquarters, tehsil towns, block development centres and gram panchayat centres. The national and the state capitals are in reality important metropolitan cities; headquarters of districts and even tehsils are recognized urban places.

At a block level, block headquarters are large villages but not recognized as urban places. Gram panchayats as per their definition are rural in nature, though they provide a wide variety of services to hamlets; they can be said to be central places of the lowest order.

Ratio comparison: The administrative hierarchy of settlements in India differs considerably from the central place system under the administrative principle as pointed out by Christaller. Theoretically, there is a ratio of 1:7 between the number of settlements of higher and lower orders. In India, the ratio of districts to state is almost 1:19, while gram panchayats per community development block may reach up to 40 in number. Also, the number of tehsils per district is slightly over six and this corresponds to the administrative principle quite closely.

1. The Central Place Theory is majorly criticized for its oversimplification of the real world by making a number of assumptions.
2. Large areas of flat land are rare (assumption of CPT).
3. The positioning of settlements is generally random and not evenly spaced contrary to even spacing of settlements suggested by Christaller.
4. The hexagonal pattern is suited for theoretical development but in the real world many other complicated factors are at work.
5. The concept of perfect competition is untrue in reality with some firms making more money than others.
6. Central places are grouped into orders (second, third, and fourth) but these do not match with the theoretical expectations as there is a definite and clear ranking of centres within each other.
7. As per the theory it is expected that two third-order centres will have equal-sized areas of influence. Central Place Theory suggests that each centre’s sphere of influence for its activities at any specific level will be equal in size to every other centre’s sphere of influence. But in reality this has rarely been the case.
8. Every higher-order centre also functions as a lower-order centre in the CPT, but often lower centres have some activities which some higher centres have.
9. Consumer travel behaviour cannot be projected. Affluence, changes in taste and preferences and greater mobility enabling people to travel farther have altered demand patterns for services and goods.
10. Technological change has also brought about changes in the ways provision of goods and services are organized and located (e.g. supermarkets, mall culture, online shopping).
11. Government intervention (setting up of economic or residential base), planning and policy making (decentralization) and legislation affect future growth of various settlements outside the town.
12. Christaller envisaged each centre with a particular function whereas they have many which also change over time.
13. Central Place Theory may not have universal validity. It also cannot be pressed to explain a settlement pattern in any region. The purpose of the theory is to identify a few salient features found in certain types of settlement patterns and tools available when seeking to describe and understand a particular pattern found in the real world.