Casualty reinsurers are moving beyond traditional models as legal and social dynamics reshape loss development trends. The assumptions that underpinned reserving and pricing frameworks for decades are being challenged by new forms of volatility and longer tail exposures, said Aspen Re senior managing director, Scott Kreuzer (pictured), pointing to how societal shifts are upending decades of reserving logic.
“The old models of loss development no longer hold,” he said. “The interplay of social inflation, litigation funding, [and] changing societal attitudes towards liability has certainly extended the tail risk and complicated reserve assumptions.”
Reinsurers are responding by building underwriting frameworks that integrate forward-looking indicators, including litigation patterns, regulatory reform activity, and macro-level claims inflation benchmarks. Kreuzer said there is heightened scrutiny on how cedents are managing defense strategies. “We've seen... investment in claims and [reinsurers] trying to get their arms around how claims may be settling quicker or trying to settle them quicker,” he said.
At the portfolio level, reinsurers are urging clients to be more surgical with capital deployment. “There’s a shift from broad, homogeneous portfolios to more differentiated capital allocation,” Kreuzer said. “We're asking our clients about how they think through that, trying to put their capital into places where they would expect to get more margin.”
That shift is especially relevant in high-risk jurisdictions where large verdicts have disrupted conventional pricing assumptions. “The market is trying to do a better job of how to price for this… and which [jurisdiction] is difficult,” he said.
Kreuzer also addressed how systemic exposures - particularly cyber, climate litigation, and AI - are exposing the limitations of conventional casualty treaty structures.
“Historically, from a casualty perspective, casualty treaties assume that losses were probably largely independent events and confined within defined lines of business,” he said. “I think those assumptions are eroding as crossline correlations intensify.”
Reinsurers have responded with what Kreuzer called “incremental”, rather than transformational, changes. Common responses include tighter exclusions, broader use of aggregate caps, and the separation of cyber risks into standalone covers. “You see that with cyber, where that traditional treaty structure has gone from blended PL and cyber in one treaty to now cyber being pulled out into standalone covers,” he said.
Some clients are moving away from quota share toward tail-focused structures, such as stop-loss or event-based covers. While treaty terms are evolving, Kreuzer emphasized the importance of tapping into relevant data to understand crossline exposures. “You're not going to have one model that's going to solve for all that,” he said. “Our clients are paying for what they intend to pay for... buying reinsurance coverage for an event that might not necessarily meet that definition is hard.”
Casualty lines remain cyclical, but not all sub-classes are moving in unison. “Each of the casualty products have unique loss dynamics,” Kreuzer said, distinguishing workers’ comp from commercial auto or tech E&O. Despite these differences, reinsurers are taking a more cautious approach across the board, recognizing that underwriting discipline is the key to sustainable profitability.
“Inadequate pricing or reserving discipline can erode years of underwriting gains,” he said. “The experience of recent years has recalibrated tolerance for volatility.”
That recalibration is now embedded in underwriting strategy. “Emerging is a focus on consistency over optimism,” Kreuzer said. “Capital providers are increasingly supportive of underwriting restraint, rather than penalizing it.”
He described a cultural shift where price adequacy is no longer viewed as a differentiator but as a baseline requirement. “Growth is something that you want... but you want to get the right margin and the right return on your capital for that,” he said.
Kreuzer offered a closer look at the US casualty landscape.
“Casualty treaty demand is there,” he said. “It reflects a mix or spectrum of market maturity and also just how risk is evolving in some different places such as AI.”
Severity trends and social inflation are forcing reinsurers to revisit attachment points and re-examine limit strategies. “Selection, attachment, coverage and price really matter,” he said, describing the fundamentals of underwriting.
“Many clients are reducing offered limits, leading to a market characterized by lower line sizes and tighter participation,” Kreuzer said.
Reinsurers, in turn, are becoming more discerning with their partnerships. “Favoring cedents that invest in analytics, claims management, and governance capabilities that reinforce portfolio stability through the cycle,” Kreuzer said.
That selectivity goes beyond technical consistency. Kreuzer said it involves active engagement with trading partners and a clear view of how they are investing in tools and processes to manage volatility. “Ensuring that they're investing in the areas that will help contain the volatility that we're seeing - that’s an important part for us.” In this environment, underwriting conviction that is supported by insight, discipline and collaboration is becoming a defining competitive advantage.
