Correlation 1 in fully segmented market

There a reading in session 6 where we need to calculate equity risk premium of the market. We need to calculate the risk premium assuming it is fully segmented and integrated. My question is why would correlation=1 in a fully segmented market? Shouldnt it be 0

In a fully segmented market, the correlation measured is between the local market portfolio for the country and the security. It is not the global portfolio and the security.