There has been a myth in the United States, which is that over 50% of the married couples in United States will end in divorce. If true, it will bring a lot of irreparable damages to children, families, and the taxpayers. Are we able to debunk the myth from the 3 common measures of divorce?

**Measure 1: The Crude Divorce Rate **

The crude divorce rate is perhaps the most common measure of divorce rate used by the statistical agencies. Here is the formula for the crude divorce rate in the U.S.:

The Crude Divorce Rate in the U.S. =

This graph shows the average number of divorces per 1,000 people in the U.S. population each year. The average number of divorces fluctuates between 2 to 5 divorces per 1,000 people in the United States. Since 1980, the crude divorce rate has been falling continuously to less than an average of 3 divorces per 1,000 people in 2018. It tells us that the number of divorces is showing a decreasing trend.

Although the crude divorce rate is an easy way to measure divorce, it has some limitations. The first and the biggest problem is that the mid-year population used to calculate the number includes children and single adults, who cannot divorce. Therefore, if we hope to focus on the number of divorces in the married population only, this rate may not be able to give us a precise number. On the other hand, the age structure of the population may also greatly affect the rate. For example, if the country has a larger proportion of children in its population, the divorce rate will be lower. This makes it difficult to compare across countries and over time.

Nevertheless, the crude divorce rate is often used to compare divorces across countries, since it is the most common measure of divorce. We can easily obtain the numbers of different countries online and make comparisons. It serves as an imperfect proxy for us to study divorce.

**Measure 2: The Refined Divorce Rate **

If we hope to focus solely only on the number of divorces in the married population, the refined divorce rate would be a better measure. Here is the formula for the refined divorce rate in the United States:

The Refined Divorce Rate in the U.S. =

Source: Institute for Family Studies

This graph shows the average number of divorces per 1,000 married women in the mid-year population of the U.S. each year. This time the number is greater than that of the crude divorce rate in every year, with the smallest number of 9.2 in 1960, and the largest number of 22.6 in 1980. Again, the number has been falling continuously since 1980, but not as quickly as that of the crude divorce rate. In 2018, there is an average of 15.1 pair of couples divorced per 1000 married women.

The refined divorce rate provides us a better measure of divorces occurred in a country. However, the divorce rate can be studied not only in terms of number, but also by the average length of marriages, or even by age at divorce. If we hope to study divorces from these perspectives, we must look for other measures since the refined divorce rate may not be able to provide such information.

**Measure 3: The Shares of Marriages Ending in Divorce**

The share of marriages ending in divorce shows us the average length of marriages. It separates married couples into different cohorts by the decades they married. Comparing with the crude divorce rate and the refined divorce rate, this measure tracks the cumulative percentage of couples married in different decades that have ended up in divorce after certain years.

Here is the formula for the share of marriages of decade y ending in divorce after x years:

Share of Marriages of Decade y Ending in Divorce After x Years =

Here comes an example: Suppose there are 100 pairs of couples married in 1991, and another 100 in 1996. Now there are a total of 200 pairs of couples married in 1990s. Then, if 30 pairs of couples married in 1991 divorced after 3 years (in 1994), and 25 pairs of couples who married in 1996 divorced after 3 years (in 1999), the share of marriages ending up in divorce after 3 years in the 1990s would be:

^{30 + 25} ⁄ _{200} x 100 = 27.5%

This graph shows the measure in 2007. It separates the married couples by the decades they married, from the 1950s to the 1990s in the U.S.. The horizontal axis shows the number of years after a pair of couple held their wedding. Therefore, the curves representing the couples married in the 1950s and 1960s are the longest, since their weddings were already held over 25 years ago.

We can compare across different decades by drawing a vertical straight line at a point from the horizontal axis and intersects the curves. For example, if we hope to investigate the shares of the married couples ended up in divorce 5 years after the wedding, we can draw a vertical straight line from the point “5 years” on the horizontal axis, then intersect all the four curves. The blue vertical straight line drawn in the graph below is the demonstration:

We can see that for the couples married in 1950s, only a very small fraction of couples of about 10%, has ended up in divorce within 5 years after the wedding. The percentage of couples ended up in divorce within 5 years after the wedding has been rising from 1960s to 1980s. Then, there is a small drop in the number of that of in 1990s.

If we want to study for a longer period, we may draw a vertical straight line from the point “25 years” on the horizontal axis and intersects the curves. The green vertical straight line drawn in the graph below is the demonstration:

For the couples married in the 1970s, almost 50% of them have already ended up in divorce within 25 years. It may be the reason why some say that 50% of the married couples will end up in divorce. However, we can also see that there is only about 40% of the couples married in 1960s ended up in divorce within 25 years. The number of that of in 1950s is even smaller, with only about 25%.