Though not always apparent to the outsider, the cultures of the tribal peoples of northern Thailand are quite distinct from each other. One point where the distinction is clear is the marriage customs of each group. While ceremonies for each tribe follow the general format of feasting and paying respect to elders, specific points such as "bride price" and cohabitation rules are quite different and can a deterrent (or stimulus) for people from different tribes to marry each other.
Tribe
Bride Price*
Marriage Ceremony
Cohabitation
Divorce
Lisu
30,000 - 50,000 Baht
The groom's family makes all arrangements.
The bride will move to live with the groom's family.
If the husband divorces the wife, the wife's family does not return the bride price.

If the wife seeks a divorce, the wife's family is obligated to return the bride price only if she has lived with her husband less than 3 months.

Akha
There is no formal bride price, but the groom must provide the costs of the wedding celebration.
The groom's family makes all arrangements.
The bride will live with the groom's family, but the couple is obligated to help both sets of parents with their farm work.
If a husband seeks to divorce his wife, he will be fined 1,500 Thai baht.

If a wife seeks to divorce her husband, she will be fined 500 baht  
Hmong
10,000 - 50,000 Baht or the equivalent in silver.

For American Hmongs the bride price is $6,000-8,000 US.

A woman who has been married before can accept a second bride price only if she returns the first.

The groom's family makes all arrangements.
The bride moves to live with the groom's family.

If the husband divorces the wife, the wife's family will not return the bride price.

If the wife divorces the husband, her family will return the bride price.

Mien
10,000-50,000 Baht
The groom's family makes all arrangements with the exception of the case in which a family has no sons, only daughters. In this case, the daughter may propose to her boyfriend and all arrangements for the wedding will be made by the bride's family.
The bride will live with the groom's family, except in the case where the bride initiated the marriage proposal. In this case, the couple will live with the bride's family.

If the husband divorces the wife, the wife's family does not return the bride price.

If the wife divorces the husband, the wife's family must return twice the original bride price.

Lahu
There is no formal bride price, but the groom must provide the costs of the wedding celebration.
The groom's family makes all arrangements.
The bride may live with the groom's family for one or two years, after which the couple will move to the bride's village and establish their own household.
Two different procedures are common. A divorce can be obtained (by either husband or wife) for 500 baht, or village elders can make both husband and wife perform farming labor as punishment.
Karen
There is no bride price, but the more charming boys often buy engagement gifts for their brides.
The bride's family makes all arrangements.
The groom will live with the bride's family.
Divorce is no-cost, but is not widely accepted.
* Bride Price - Common throughout Asian cultures, the bride price is a sum of money that the groom pays to the parents of the bride when asking for her hand in marriage. The bride price is indicative of the social standing of the groom and the desirability of the bride. In some cases the bride's family returns the bride price to the newlyweds as a nest egg for starting their family. The custom of bride price endures in part because of the belief that if one does not spend money to acquire his wife, he will not have proper motivation to take care of her, but with an average income of less than 3,000 baht per month, many tribal people are finding the bride price an excessive burden. As the tribal groups interacting with each other more than ever, the bride price has become a stimulus for intermarriage. The most notable trend is Lisu men marrying Akha women, who require no bride price. It is also common to see a northern Thai married to either an Akha or Lahu woman for this reason.