Dividend income rose 13 percent in 2014 while interest income rose 1 percent, driving a net increase in pretax investment income of $20 million, or 4 percent. In addition to a larger common stock portfolio generating more dividend income in both 2014 and 2013, both years also benefited from higher average dividend payment rates. Our investment operation’s performance is discussed further in Investments Results.
We measure profit or loss for our commercial lines, personal lines and excess and surplus lines and life insurance segments based upon underwriting results (profit or loss), which represent net earned premium less loss and loss expenses and underwriting expenses on a pretax basis. We also frequently evaluate results for our consolidated property casualty insurance operations, which is the total of our commercial, personal, and excess and surplus lines insurance results. Underwriting results and segment pretax operating income are not substitutes for net income determined in accordance with GAAP.
Catastrophe losses, as discussed in Consolidated Property Casualty Insurance Results, explain much of the movement in current accident year loss and loss expense ratios for accident years 2014 and 2013, compared with 2012. Catastrophe losses added 8.8 percentage points for both 2014 and 2013, and 18.4 points for 2012 to the respective personal lines current accident year loss and loss expense ratios in the table above. Personal lines catastrophe losses for 2014 and 2013 were basically in line with our 8.7 percent 10-year annual average for the years 2001 through 2010, while 2012 was much higher than that historical average. Personal lines catastrophe losses also are inherently volatile, as discussed above and in Consolidated Property Casualty Insurance Results.
The general market view is that, in light of Federal Reserve commentary, interest rates are likely to remain below historic averages for at least the next two years. This will continue to apply pressure on investment income.
Revenues and expenses in 2014 for our Other operations each decreased slightly, compared with 2013. Other includes noninvestment operations of the parent company and its commercial leasing and financial services subsidiary, CFC Investment Company. Losses before income taxes for Other were largely driven by interest expense from debt of the parent company.
We had $196 million of income tax expense in 2014 compared with $197 million in 2013 and $145 million in 2012. Our corporate effective tax rate for 2014 was 27.2 percent compared with 27.6 percent in 2013 and 25.6 percent in 2012.
continue to monitor our claims for evidence of material exposure to other mass tort classes such as silicosis, but we have found no such credible evidence to date.
We direct our associates and agencies to settle claims and pay losses as quickly as is practical, and we made $2.413 billion of net claim payments during 2014. At year-end 2014, total net property casualty reserves of $4.156 billion reflected $2.091 billion in unpaid amounts on reported claims (case reserves), $920 million in loss expense reserves and $1.145 billion in estimates of claims that were incurred but had not yet been reported (IBNR). The specific amounts and timing of obligations related to case reserves and associated loss expenses are not set contractually. The amounts and timing of obligations for IBNR claims and related loss expenses are unknown. We discuss our methods of establishing loss and loss expense reserves and our belief that reserves are adequate in Critical Accounting Estimates, Property Casualty Insurance Loss and Loss Expense Reserves.
Overall favorable development for consolidated property casualty reserves of $98 million in 2014 illustrated the potential for revisions inherent in estimating reserves, especially for long-tail lines such as commercial casualty and workers’ compensation. As noted in Critical Accounting Estimates, Key Assumptions Loss Reserving, our models predict that actual loss and loss expense emergence will differ from projections, and we do not attempt to monitor or identify such normal variations. The table in Property Casualty Loss and Loss Expense Obligations and Reserves shows reserves by segment and lines of business and the components of gross reserves among case, IBNR and loss expense reserves.
Commercial casualty adverse development for prior accident years - During 2014, we experienced unanticipated claims development on prior accident years, especially for umbrella liability coverage. That included an increase in aggregate paid losses or loss expenses for accident years three or more years old. Those payments emerged at levels higher than we expected, particularly for accident years 2005 and 2007. Considering that new data, our actuaries responded cautiously, and we increased our estimates for IBNR losses and loss expenses for all prior accident years in total. Our products liability coverage within commercial casualty experienced a higher-than-anticipated 2014 increase in paid losses or loss expenses, primarily for more recent prior accident years. That increase, plus an approximately equal increase in reserves, resulted in net unfavorable or adverse development on prior accident years for products liability. In 2014, our medical professional liability coverage within commercial casualty experienced net favorable development on prior accident years, but less so than in 2013, when it was more than twice the annual average of years 2010 through 2012.
Increased frequency and/or severity of claims or development of claims that are unforeseen at the time of policy issuance
Domestic and global events resulting in capital market or credit market uncertainty, followed by prolonged periods of economic instability or recession, that lead to: