What is one example of a social contract?

Social contracts can be explicit, such as laws, or implicit, such as raising one's hand in class to speak. The U.S. Constitution is often cited as an explicit example of part of America's social contract. It sets out what the government can and cannot do.

for starters, there is the structural trend of rising primary government expenditure as a share of gdp, which reached 36% in 2014, up from 22% in 1991. this increase reflected a political desire to address the poverty and inequality that had gone unaddressed during previous decades. to support the increase, brazil’s government increased taxes on consumption and promoted progress toward labor-market formalization. nonetheless, public investment, particularly in infrastructure, took a hit. in fact, with the exception of the 2005-2008 period, total investment as a share of gdp has remained below 20% since 1991.

i think they would live in caves or natural tunnels