The most talked-about topic affecting everyone for now almost a year is inflation. Your money loses its purchasing power, you need more money to buy the same amount of goods and services you purchase or use. If you are hiding a lot of money under your mattress or in a safe place at home, trust me it’s a bad idea. You will only be able to buy fewer items with that in the future than now.
The easiest way to define inflation to a layman is the sustained increase in the average prices of a basket of goods and services that we buy over a specific period. So, when there is inflation, the cost of living goes up. This becomes a real problem if your income doesn’t rise as quickly as inflation, then with your current income, you will only be able to buy less same stuff than before.
The inflation rate is expressed as a percent change from the previous period. Below is the actual inflation rate in the US in the last 6 years. So if the annual inflation is 6%, it means on average, prices have risen 6% from the last year. As you can see, the inflation slope became steeper in 2020, after the pandemic hit the global economy.
So, what causes inflation?
This can happen in two ways: either through demand-pull factors or through cost-push factors.
The quantity theory of money explains inflation caused by demand-pull factors.
Demand-pull inflation
This occurs when people have too much money and they want to buy more, whereas there is not enough supply to meet that demand. Or in other words, too much money is chasing too few goods. This usually happens when the economy is at (or very close to) full employment/full capacity. By full employment, we mean people who are looking for jobs can find one. Also, in this situation, the country’s GDP grows at a rate faster than its long-run trend rate. This happens when there is too much money in circulation. If the bank interest rates are too low, people, both households and businesses can borrow easily and as a result, can buy more goods and services than what the firms can supply. We call this phenomenon “too much money chasing too fewer goods”. Producers increase prices and profit because they can’t increase supply in the short run.
Using the demand and supply curves, I explain this idea. You see that the demand curve always slopes downwards, meaning people always want to buy more items at a lower price, Also, note that the supply curve faces upward, which means the firms producing those goods would like to supply more at higher prices, With the same assumption that is everything else staying the same. Equilibrium price and quantity are established at P and Q where the supply and the demand curve meet. We call them P and Q.
To explain this graphically, let’s look at the demand and supply model. On y axis, we denote the general price level, since inflation reflects general price level rise. On x asis we will show the real quantity of goods and services or real GDP. In the graph below, demand will be aggregate demand as this is represents demand from the whole economy. This demand is also downward sloping curve, as the demand for any normal item will be. It shows people overall demand lower quantities when the prices are high and demand more quantities when the prices are low. With the same assumption that nothing else is affecting the demand and everything else stays constant. The aggregate supply curve always is upward sloping meaning producers are willing to supply more at higher prices, so they can get more profits and vice versa. With the assumption that everything else is staying the same, the price level and quantity are set where aggregate demand meets aggregate supply at e. This is the price level consumers are willing to pay and producers are willing to accept and is denoted by P. And the corresponding quantity supplied and demanded is denoted by real production of goods and services or real GDP at Q. Economist call this equilibrium price level and quantity.
If there is excess money in circulation in the economy, people can afford to buy more, so for each price level, there is an increased demand. Or in other words, too much money is chasing fewer goods.
In our graph, you will see the aggregate demand shifting to the right or upwards. Now we get the new equilibrium e1, where the new demand and supply meet, and you can see that the new price and the quantity both have increased to P1 and Q1. This happens in the short run when producers don’t increase the supply of goods and services but instead, charge more prices because of increased demand.
Over time when producers can increase their production, the supply will be increased. In the graph below, this will mean the supply curve shifts to the right. So we can see at the new equilibrium, the prices will fall back. How much the prices fall, will depend on how much adjustment (increase) in supply is made in the long run. If the supply is adjusted enough to meet the increasing demand, then the prices will back to level P and the quantity demanded and supplied will be even higher, as shown at Q2. And the increase in the general price level is controlled.
Cost-push inflation
When the supply of the good is reduced due to an increase in the price of inputs in making that good or service. Supply shocks can cause cost-push inflation. Supply can fall due to a variety of reasons, such as if the cost of inputs for production goes up or if there is a natural calamity. Most recently after the pandemic, lockdown jams in major ports have contributed to a slowdown in the supply of a lot of items.
In the graph above, supply shock has pushed the price up to P1, and Quantity is reduced to Q1.
How to calculate the inflation rate?
Inflation is expressed as a % change in the price level of a market basket of goods and services over a period. To understand how inflation is calculated, let’s start with a very simple economy, where people only bought and consumed 3 items – bread, internet, clothing, and a house. You spend 30% of your yearly income on bread, 10% on clothing, 10% on the internet and 50% on renting an apartment. Then let’s assume the price of bread in year 1 is $2 and the price of internet is $45, price of clothing is $10, and rent is $25000. The price of bread in the year 2022 goes up to $2.5, price of internet becomes $60, price of clothing increases to $15 and rent in year 2 is $30000. We also, in the table below, list the proportion of income or weight they spend on all these items. The sum of these weights needs to add to 100%.
Inflation from year 1 to year 2 is calculated as (CPI2 – CPI1)/ CPI1 * 100 where CPI1 is the price level in year 1 and CPI2 is the price level in year 2. CPI is a weighted average price of many day-to-day goods and services that a typical American person living in a city buys at a particular time. Don’t be frightened by the term “weighted average”. Weight here refers to the importance of spending on a particular item compared to total expenditure. It simply means more weight is given to goods and services where you spend more money of your income. This could be because you buy that thing more often like, daily or you spend a lot of money buying it.
If we change the weight of some things from table 1, even with the same absolute increase in price, the inflation % will change. As you can see in table 2, it became 20.02%.
If the change in prices is more compared to that from table 1, even with the same % of weight, the inflation % will be greater.
BLS calculates and publishes inflation in the US
However, our consumption is not just restricted to these four items. In fact, a typical American urban consumer consumes a wide variety of goods, known as the market basket of goods.
In the US, the Bureau of Labor Statistics calculates something called the CPI (consumer price index). To collect the monthly price data, BLS-trained representatives make personal visits, phone calls, and get online surveys to collect data on what goods and services American people are buying.
The price and weight info are essentially based on a survey of people of what proportion of their income people spend on a given good or service. BLS tries to calculate the prices of the same basket of goods and services. Now, here some people will argue that what if people don’t consume the same things after some years? That is a subject of further investigation, but the general idea is that the BLS tries to calculate the prices of the same goods and services consumed by the average person over a period for which it is calculating the inflation rate.
If you are interested, you can check the detailed report here with relative weights and price changes by category. https://www.bls.gov/news.release/pdf/cpi.pdf
Since CPI is a sample of retail prices and does not cover the complete universe of all prices, it is subject to some errors. However, that sampling error is not statistically significant to change the calculation by a lot. You will have to get into statistics class to understand the more technical aspects of what is considered a significant error or not, but for now, you can understand the error possibility is very small, so it is a reliable indicator of how the prices are behaving in general.
But when do we need to worry about inflation?
Well, some inflation is not bad and is considered healthy for the economy. Since our salary/wages have also increased over time and in most cases, some general rise in price level doesn’t hurt our purchasing power.
The BLS calculates this measure at 1-month, 3 months, 6 months, and 1-year intervals, and publishes that data. Over the last 40 years, we have seen this inflation % on average staying close to 2% annually. That means the same basket of items that you buy is 2% more expensive from 1 year to the next. The goal of monetary policy is to keep the inflation number close to this target-rate.
But in some countries like Zimbabwe and Venezuela, the prices had risen to a level making it very difficult for people to hold on to their currency. That situation where general prices rise at a rate of 50% per month is called hyperinflation. People know that they won’t be able to buy the same set of goods with that amount of money, even the very next day, so they demand more wages to cope with it. This, in turn, causes firms to pass this burden by increasing the prices of goods and services they provide. This, in turn, causes an increased demand for higher wages and the spiral continues. This is called the wage-price spiral. This can cause a severe crisis in any country.
To know more about how the Fed uses monetary policy to control inflation, click here.
Nicely explained
Comments are closed.