The idea/concept of 'spatial margins of profitability’ in context of industrial location theories was propounded by __________.

 the correct answer is  D.M. Smith.

Important Points

The idea/concept of 'spatial margins of profitability’ in the context of industrial location theories was propounded by D.M. Smith. 

Theory of Industrial Location by D. M. Smith:

• D. M. Smith presented a simple model of industrial location in his book “Industrial Location”, published in 1971.
• His model was based on his studies of Steel Mill in Brazil.
• The theory explains the idea of spatial margin locations.
• Location inside the margin would result in profit for the organization, while outside would result in loss.
• The theory is based on Spatial Margins of profitability of an industry, so it is known as 'Spatial MarginsTheory’.
• His theory is also known as the ‘Area-Cost Curve Theory’.

​ Therefore,The idea/concept of 'spatial margins of profitability’ in the context of industrial location theories was propounded by D.M. Smith. Additional Information

Area-Cost Curve Theory:​

• According to him, manufacturing costs vary in different situations and locations, so that the revenues and profits will vary within the feasible margins.
• Smith attempted to explain his theory by setting locational flexibility within a spatial range as delimited by the intersection of space cost curves and space revenue curves.
• This can be explained with the help of a graphic presentation.
• In the figure, the x-axis shows that the distance increasing from left to right, and the y-axis denotes the number of costs and revenues.
• Cost is indicated by the downward line and revenue is shown by the upward line in the image above.
• At two points the quantity of cost and revenue will be equal, A and D.
• The area between A to D is profitable for the industry.
• The point 'B' showing the highest revenue while the line joining 'B' passes through the lower cost point. The range is maximum in this location.

It is clearly depicted that the space-revenue curve would be 'A-shaped' in D. M. Smith's theoretical model of the spatial margins to profitability.