Markets & Economic Sectors
What Is a Market?
When you buy a bus pass, your school orders exercise books, or a landlord rents out a flat, each of those transactions takes place in a market. A market does not have to be a physical place — it is simply any arrangement that brings buyers and sellers together. The stock market operates entirely online. The market for second-hand cars takes place on forecourts, websites and car-boot sales at the same time.
What all markets share is a process of exchange: one party offers something, another party is willing to pay for it, and together they settle on a price. This price sends a signal to everyone else in the market. When the price of petrol rises sharply, drivers cut unnecessary journeys and manufacturers look for cheaper fuel alternatives. The price does not just measure the exchange — it co-ordinates the behaviour of millions of people without any single person directing them.
A market is any opportunity for buyers and sellers to interact in order to establish a price. Markets can be physical (a street market), virtual (eBay) or abstract (the foreign-exchange market).
How Markets Allocate Scarce Resources
Resources are scarce — there are never enough land, labour, capital and enterprise to produce everything everyone wants. Someone must decide what gets produced, how it is produced, and who receives it. In a market economy, those decisions are made through the price mechanism rather than by a central planner.
Think about how this works in the housing market. Demand for homes in city centres is very high; supply is limited. Prices rise. High prices signal to builders that there are profits to be made, so they invest in new construction. Over time — though it can take years — more homes are built and prices moderate. Conversely, if fewer people want to live in a particular town, house prices fall, sending a signal that resources are better used elsewhere. The price mechanism performs three functions simultaneously: it rations the good (only buyers willing to pay the price get it), it signals where resources are needed, and it incentivises producers to respond.
Markets can be divided into two broad types. A factor market is where the inputs to production are traded. The labour market is the most familiar example: firms demand workers and households supply their time and skills, with wages settling at the price where supply meets demand. The market for commercial property is a factor market too — businesses rent factory space and offices.
A product market is where finished goods and services are sold to consumers. The market for smartphones, the market for cinema tickets and the market for takeaway food are all product markets. In a product market, households are the buyers and firms are the sellers — the reverse of a factor market, where firms buy and households sell.
The Three Economic Sectors
Economists divide economic activity into three sectors based on what stage of production is involved. Understanding which sector a business operates in helps us analyse how an economy has changed over time.
The primary sector involves extracting raw materials from the natural environment. A farmer growing wheat, a fishing crew landing a catch, a coal miner cutting seams underground and a forester felling timber are all working in the primary sector. The output is unprocessed — it comes directly from land, sea or underground.
The secondary sector takes those raw materials and turns them into something else. A bakery turning wheat into bread, a car plant turning steel into vehicles, and a construction company building houses are all in the secondary sector. The key activity is manufacturing or processing — adding value to a raw input.
The tertiary sector provides services. A supermarket selling that bread, a bank offering a mortgage, a teacher delivering a lesson, a delivery driver bringing a parcel, a nurse treating a patient — all are in the tertiary sector. No physical good is produced; the value lies in the service itself.
The three sectors are: primary (extract raw materials — e.g. farming, fishing, mining), secondary (manufacture goods — e.g. car production, construction) and tertiary (provide services — e.g. retail, banking, healthcare). In the modern UK, the tertiary sector is by far the largest.
How the Sectors Have Changed in the UK
The relative size of each sector in the UK has shifted dramatically over the past century. In the nineteenth century, the UK was the “workshop of the world”: a huge secondary sector dominated the economy, employing millions in steel mills, shipyards and textile factories. Today that picture looks entirely different.
The primary sector now accounts for a very small share of UK output and employment. Mechanisation of farming, the closure of deep coal mines and the decline of fishing have all reduced the numbers working in primary activities. The secondary sector has also shrunk significantly — a process economists call deindustrialisation. Factories have closed or moved abroad where labour costs are lower, and the UK has shifted away from mass manufacturing.
The tertiary sector now generates the vast majority of UK GDP and employment. Financial services, retail, hospitality, education and healthcare are among the largest employers. Cities like London are global centres for banking and insurance — activities that did not even exist in their modern form a century ago.
Several factors explain why UK manufacturing has declined relative to the service sector. First, global competition: firms in countries with lower wages — such as those in parts of Asia — can produce many manufactured goods more cheaply than UK firms. Second, automation: robots and computer-controlled machinery have replaced manual workers on production lines, so the same level of output requires fewer employees. Third, rising incomes: as people become wealthier, they tend to spend a higher proportion of their income on services — holidays, restaurants, streaming, healthcare — rather than extra manufactured goods. This shifts demand towards the tertiary sector.
Deindustrialisation is not inherently bad: the UK has gained highly productive, high-wage service jobs in finance, technology and the creative industries. However, the transition has been painful for many communities, particularly in the Midlands, South Wales, the North East and parts of Scotland, where manufacturing was the main employer. Structural unemployment rose sharply in those areas when factories closed, because workers’ skills did not immediately transfer to the new service jobs.