Revert "add chengchi"
Revert "add chengchi"

This reverts commit 0d3e9eea25f19c02d3ce0a62cde78a2c6a9ea0cb.

compsocialscience/summer-institute,compsocialscience/summer-institute,compsocialscience/summer-institute,compsocialscience/summer-institute,compsocialscience/summer-institute,compsocialscience/summer-institute