For AM Best, one of the key questions for casualty reinsurers is whether recent rate increases are keeping pace with underlying loss costs. These participants often identify 2019 as an important turning point in casualty underwriting conditions. The issue is particularly significant for traditional reinsurers because casualty liabilities can take years to develop. A substantial part of the economics of casualty reinsurance comes from investment income earned between the receipt of premium and the payment of claims. The agency also notes concerns raised by some traditional reinsurers about whether investors fully understand the risks being transferred, particularly where structures combine uncertain claims development with investment exposure.