This study seems fairly plausible to me:
Does Divorce Law Affect the Divorce Rate? A Review of Empirical Research, 1995-2006
Did the introduction of no-divorce law affect the divorce rate? This study looks at all the empirical research since 1995 that examines the impact of no-fault divorce laws on divorce rates both in the United States and in other nations, 24 studies in all, and concludes:
- No-fault divorce did increase the divorce rate. Seventeen of 24 recent empirical studies find that the introduction of no-fault divorce laws increased the divorce rate, by one estimate as much as 88 percent. More typically, studies estimate no-fault divorce increased divorce rates on the order of 10 percent.
- Divorce law, however, is not the major cause of the increase in divorce over the last 50 years. Clearly many other factors besides divorce law influence the divorce rate.
- The effect of no-fault divorce laws on the overall divorce rate appears to fade with time; couples respond to the increased divorce risk from no-fault divorce law by delaying or forgoing marriages at higher risk of divorce, and states adopt related legal reforms that mitigate some of no-fault’s consequences.
- For couples of a given match quality, no-fault divorce may have resulted in a permanent increase in divorce risk. Studies which take into consideration age at marriage tend to show a permanent increase in divorce risk after no-fault divorce.