LAMP - Weights
The LAMP database provide community- and sample-specific weights: for each community, you will see a single weight for all the households in the home country sample and another weight for all the households in the U.S. sample. In the case of surveys that included migration to a third country (such as the Nicaraguan surveys, which inquired about migration to the United States and to Costa Rica), there is an additional weight for the third country sample.
When working with pooled data from multiple communities, these weights give you the option of adjusting your estimates so as to take into accouunt the relative sizes of all the sampling frames. Whether you will need to weight your estimates or not will depend on what your goal is. The document below contains a detailed explanation on our computation of the weights, and suggests criteria to use them or disregard them. Since the Mexican Migration Project (MMP) and the LAMP apply the same methodology, the document is valid for both projects. For the sake of the example, the text focuses on MMP134, the MMP database. Yet, all it says is entirely applicable to the LAMP databases as well.