Marriages were viewed as permanent but were usually short-lived. (Gottlieb, 1993) Many marriages today last only 10-20 years, but the dissolution occurs for a very different reason, divorce. In fact, more than half of all marriages will end in divorce or separation by the 20th year. (Pinsof, 2002) .
Another theory suggests that divorces have become more popular due to the decrease of birth rates and the increase in women's income. Having one child reduces the likelihood of divorce by 30% between the fifth and fifteenth year of marriage, and having two children reduced the rate by another 30%. The number of births per family has partly decreased due to the rise in employment and careers among wives. The newly found income has given women a choice, allowing them to rely less on a husband for financial security. An increase in wives" financial security has also influenced marital power dynamics. (Rogers & DeBoer, 2001) These two variables (low birth rate and women's employment) are very similar in the fact that they give women a choice. (Pinsof, 2002) .
It appears that the government and the politics that surround it also play a role in the increased divorce rates over the last several decades. The implementation of the no-fault and unilateral divorce laws was intended to be a response to more liberal views of divorce, but it actually triggered an increase in the number of divorces. In fact, it is projected that the divorce rate would have been 6% lower in 1988 had these laws not been passed. (Friedberg, 1998) The government and society has made it easier to obtain a divorce, reduced the social and legal stigma associated with divorce, and reduced the trauma (blame and character assassination) associated with divorce. (Pinsof, 2002).
There are two critical periods in which divorce usually occurs. The first period is marriage through year seven and the second is midlife. Researchers have discovered a way to determine if a couple will divorce in the first or second critical period.