The credit spread reflects the additional yield over the risk-free rate that investors demand to compensate for the risk of default. An increase in the probability of default of the issuer (I) would directly increase the credit spread as investors require more return for higher risk. Similarly, an increase in expected loss (IV) would increase the credit spread since the potential loss in the event of default is greater. On the other hand, a decrease in risk premium (II) or a decrease in loss given default (III) would typically lower the credit spread, not increase it.