SEVEN ECONOMIC RULES: A set of seven fundamental notions that reflect the study of economics and how the economy operates. They are: (1) scarcity, (2) subjectivity, (3) inequality, (4) competition, (5) imperfection, (6) ignorance, and (7) complexity.
What is the Rule of 72? The Rule of 72 is a calculation that estimates the number of years it takes to double your money at a specified rate of return. If, for example, your account earns 4 percent, divide 72 by 4 to get the number of years it will take for your money to double. In this case, 18 years.
The rule of 70 offers a way to figure out the doubling time of an investment. In other words, it shows you how many years it will take for your initial deposit to double in size. You'll need to know the specific rate of return in order to use the rule of 70 or doubling time formula.
The rule of 70 is useful for all sorts of applications. For example, if you've saved some money in an investment account that's growing at 5% per year, you can divide 70 by 5 to get an approximation for how quickly your savings will double.
Explanation of the Rule of 70
The formula is as follows: Take the number 70 and divide it by the growth rate. The result is the number of years required to double. For example, if your population is growing at 2%, divide 70 by 2. The result is 35; it will take 35 years for your population to double at a 2% growth rate.
The Rule of 69 is used to estimate the amount of time it will take for an investment to double, assuming continuously compounded interest. The calculation is to divide 69 by the rate of return for an investment and then add 0.35 to the result.
The rule of 72 is best for annual interest rates. On the other hand, the rule of 70 is better for semi-annual compounding. For example, let's suppose you have an investment that has a 4% interest rate compounded semi-annually or twice a year. According to the rule of 72, you'll get 72 / 4 = 18 years.
If an economy grows at 2% per year, it will take 70 / 2 = 35 years for the size of that economy to double. If an economy grows at 7% per year, it will take 70 / 7 = 10 years for the size of that economy to double, and so on.
Do you know the Rule of 72? It's an easy way to calculate just how long it's going to take for your money to double. Just take the number 72 and divide it by the interest rate you hope to earn. That number gives you the approximate number of years it will take for your investment to double.
The Rule of 72 is a simple way to determine how long an investment will take to double given a fixed annual rate of interest. By dividing 72 by the annual rate of return, investors obtain a rough estimate of how many years it will take for the initial investment to duplicate itself.
The rule of 70 is used to determine the number of years it takes for a variable to double by dividing the number 70 by the variable's growth rate. The rule of 70 is generally used to determine how long it would take for an investment to double given the annual rate of return.
The Rule of 70 assumes a constant rate of growth or return. As a result, the rule can generate inaccurate results since it does not consider changes in future growth rates.
Basically, the rule says real estate investors should pay no more than 70% of a property's after-repair value (ARV) minus the cost of the repairs necessary to renovate the home. The ARV of a property is the amount a home could sell for after flippers renovate it.
What is Rule of 69. Rule of 69 is a general rule to estimate the time that is required to make the investment to be doubled, keeping the interest rate as a continuous compounding interest rate, i.e., the interest rate is compounding every moment.
Answer and Explanation: It will take a bit over 10 years to double your money at 7% APR. So 72 / 7 = 10.29 years to double the investment.
While get-rich-quick schemes sometimes may be enticing, the tried-and-true way to build wealth is through regular saving and investing—and patiently allowing that money to grow over time. It's fine to start small. The important thing is to start, and to start early. Earn money and then save and invest it smartly.
Key Takeaways. The Rule of 72 is a simplified formula that calculates how long it'll take for an investment to double in value, based on its rate of return. The Rule of 72 applies to compounded interest rates and is reasonably accurate for interest rates that fall in the range of 6% and 10%.
Instead of needing to double your capacity in 36 years, you only have 24. Twelve years were shaved off your schedule with one percentage point faster growth. The Rule of 72 was originally discovered by Italian mathematician Bartolomeo de Pacioli (1446-1517).
You can also apply the Rule of 72 to debt for a sobering look at the impact of carrying a credit card balance. Assume a credit card balance of $10,000 at an interest rate of 17%. If you don't pay down the balance, the debt will double to $20,000 in approximately 4 years and 3 months.
Driven by industrial production and manufacturing exports, China's GDP is actually now the largest in terms of purchasing power parity (PPP) equivalence. Despite this growth, China's economy remains strictly controlled by its government where there are accusations of corruption, unfair dealings, and falsified data.
Answer and Explanation: If the price increases by the inflation rate, it will take 10.24 years for the cost of something to double.
The adoption of economic reforms by China in the late 1970s led to a surge in China's economic growth and helped restore China as a major global economic power. Source: The Organization for Economic Cooperation and Development, Chinese Economic Performance in the Long Run, 960-2030, by Angus Maddison, 2007.
The Rule of 72 explains the miracle of compounding interest.
It is alleged that Albert Einstein referred to compound interest as the “most powerful force in the universe” or the “greatest mathematical discovery.” However, no proof can be found that Einstein ever mentioned the Rule of 72, much less invented it.
To use the rule, divide 72 by the investment return (the interest rate your money will earn). The answer will tell you the number of years it will take to double your money. For example: If your money is in a savings account earning 3% a year, it will take 24 years to double your money (72 / 3 = 24).
The 10,5,3 rule
Though there are no guaranteed returns for mutual funds, as per this rule, one should expect 10 percent returns from long term equity investment, 5 percent returns from debt instruments. And 3 percent is the average rate of return that one usually gets from savings bank accounts.