Mr. Chiswick and Mr. Passel spoke on the United States immigration policies, focusing on their economic and social impact. President Bush signed into law on November 29, 1990, the first major changes in immigration policies in 25 years. The new laws increased the number of immigrants allowed into the United States, allowing a greater number of family members of admitted immigrants into the country, and set a number of “diversity quotas” which were designed to limit the number of immigrants from Latin America and Asia while stimulating immigration from other countries.