The following tables present segment results for Alleghanys three reportable segments and for corporate activities for 2019, 2018 and 2017: Reinsurance Segment Insurance Segment Year Ended December 31, 2019 Property Casualty &amp; other (1) Total RSUI Cap Specialty Total Subtotal Alleghany Capital (2) Total Segments Corporate Activities (3) Consolidated ($ in millions) Gross premiums written $ 1,700.3 $ 3,245.4 $ 4,945.7 $ 1,366.6 $ 371.8 $ 1,738.4 $ 6,684.1 $  $ 6,684.1 $ (27.7 ) $ 6,656.4 Net premiums written 1,328.8 3,166.2 4,495.0 912.0 344.7 1,256.7 5,751.7  5,751.7  5,751.7 Net premiums earned 1,280.1 3,046.9 4,327.0 824.2 326.9 1,151.1 5,478.1  5,478.1  5,478.1 Net loss and LAE 942.6 2,018.5 2,961.1 503.7 221.6 725.3 3,686.4  3,686.4  3,686.4 Commissions, brokerage and other underwriting expenses (4) 424.2 982.6 1,406.8 219.2 132.7 351.9 1,758.7  1,758.7  1,758.7 Underwriting (loss) profit (5) $ (86.7 ) $ 45.8 $ (40.9 ) $ 101.3 $ (27.4 ) $ 73.9 33.0  33.0  33.0 Net investment income 533.2 6.3 539.5 10.7 550.2 Change in the fair value of equity securities 705.8  705.8 3.9 709.7 Net realized capital gains 6.0 1.0 7.0 (13.5 ) (6.5 ) Other than temporary impairment losses (19.7 )  (19.7 )  (19.7 ) Noninsurance revenue 27.0 2,289.3 2,316.3 12.5 2,328.8 Other operating expenses 103.1 2,132.9 2,236.0 27.3 2,263.3 Corporate administration 4.1  4.1 70.7 74.8 Amortization of intangible assets 1.3 32.5 33.8  33.8 Interest expense 27.1 20.1 47.2 52.8 100.0 Earnings (losses) before income taxes $ 1,149.7 $ 111.1 $ 1,260.8 $ (137.2 ) $ 1,123.6 Reinsurance Segment Insurance Segment Year Ended December 31, 2018 Property Casualty &amp; other (1) Total RSUI Cap Specialty Total Subtotal Alleghany Capital (2) Total Segments Corporate Activities (3) Consolidated ($ in millions) Gross premiums written $ 1,532.7 $ 2,918.3 $ 4,451.0 $ 1,142.0 $ 328.8 $ 1,470.8 $ 5,921.8 $  $ 5,921.8 $ (26.2 ) $ 5,895.6 Net premiums written 1,169.4 2,799.7 3,969.1 773.3 306.0 1,079.3 5,048.4  5,048.4  5,048.4 Net premiums earned 1,177.3 2,761.7 3,939.0 747.3 289.9 1,037.2 4,976.2  4,976.2  4,976.2 Net loss and LAE 1,067.8 1,801.5 2,869.3 491.2 159.9 651.1 3,520.4  3,520.4  3,520.4 Commissions, brokerage and other underwriting expenses (4) 384.9 897.4 1,282.3 211.9 123.1 335.0 1,617.3  1,617.3  1,617.3 Underwriting (loss) profit (5) $ (275.4 ) $ 62.8 $ (212.6 ) $ 44.2 $ 6.9 $ 51.1 (161.5 )  (161.5 )  (161.5 ) Net investment income 480.9 4.8 485.7 14.8 500.5 Change in the fair value of equity securities (184.2 )  (184.2 ) (44.8 ) (229.0 ) Net realized capital gains 31.6 0.9 32.5 (35.7 ) (3.2 ) Other than temporary impairment losses (1.3 )  (1.3 )  (1.3 ) Noninsurance revenue 22.0 1,574.6 1,596.6 47.4 1,644.0 Other operating expenses 59.8 1,485.6 1,545.4 33.9 1,579.3 Corporate administration (1.7 )  (1.7 ) 17.6 15.9 Amortization of intangible assets (0.4 ) 24.4 24.0  24.0 Interest expense 27.1 10.5 37.6 53.1 90.7 Earnings (losses) before income taxes $ 102.7 $ 59.8 $ 162.5 $ (122.9 ) $ 39.6 Reinsurance Segment Insurance Segment Year Ended December 31, 2017 Property Casualty &amp; other (1) Total RSUI Cap Specialty Pacific Comp Total Subtotal Alleghany Capital (2) Total Segments Corporate Activities (3) Consolidated ($ in millions) Gross premiums written $ 1,557.8 $ 2,652.8 $ 4,210.6 $ 1,056.8 $ 290.2 $ 162.6 $ 1,509.6 $ 5,720.2 $  $ 5,720.2 $ (23.3 ) $ 5,696.9 Net premiums written 1,233.1 2,577.0 3,810.1 724.4 271.2 160.2 1,155.8 4,965.9  4,965.9  4,965.9 Net premiums earned 1,181.9 2,626.8 3,808.7 721.7 260.9 163.7 1,146.3 4,955.0  4,955.0  4,955.0 Net loss and LAE 1,080.1 1,705.3 2,785.4 569.9 143.9 121.0 834.8 3,620.2  3,620.2  3,620.2 Commissions, brokerage and other underwriting expenses (4) 383.4 903.3 1,286.7 208.9 112.7 42.9 364.5 1,651.2  1,651.2  1,651.2 Underwriting (loss) profit (5) $ (281.6 ) $ 18.2 $ (263.4 ) $ (57.1 ) $ 4.3 $ (0.2 ) $ (53.0 ) (316.4 )  (316.4 )  (316.4 ) Net investment income 434.6 2.1 436.7 14.3 451.0 Change in the fair value of equity securities      Net realized capital gains 85.7 23.0 108.7 (1.5 ) 107.2 Other than temporary impairment losses (16.9 )  (16.9 )  (16.9 ) Noninsurance revenue 15.5 896.9 912.4 15.9 928.3 Other operating expenses 82.8 844.9 927.7 39.4 967.1 Corporate administration 1.7  1.7 45.3 47.0 Amortization of intangible assets (1.5 ) 20.9 19.4  19.4 Interest expense 26.9 4.0 30.9 52.1 83.0 Earnings (losses) before income taxes $ 92.6 $ 52.2 $ 144.8 $ (108.1 ) $ 36.7 (1) Primarily consists of the following reinsurance lines of business: directors and officers liability; errors and omissions liability; general liability; medical malpractice; ocean marine and aviation; auto liability; accident &amp; health; mortgage reinsurance; surety; and credit. (2) Excludes certain minor, legacy investments that were previously reflected in Alleghany Capital in 2018 and prior periods, to align with managements view of reportable segments. (3) Includes elimination of minor reinsurance activity between segments. Also, includes certain minor, legacy investments that were previously reflected in Alleghany Capital in 2018 and prior periods. (4) Includes amortization associated with deferred acquisition costs of $1,392.8 million, $1,271.4 million and $1,261.7 million for the years ended December 31, 2019, 2018 and 2017, respectively. (5) Underwriting profit represents net premiums earned less net loss and LAE and commissions, brokerage and other underwriting expenses, all as determined in accordance with GAAP, and does not include net investment income, change in the fair value of equity securities, net realized capital gains, OTTI losses, noninsurance revenue, other operating expenses, corporate administration, amortization of intangible assets or interest expense. Underwriting profit does not replace earnings before income taxes determined in accordance with GAAP as a measure of profitability. Rather, Alleghany believes that underwriting profit enhances the understanding of its reinsurance and insurance segments operating results by highlighting net earnings attributable to their underwriting performance. Earnings before income taxes (a GAAP measure) may show a profit despite an underlying underwriting loss. Where underwriting losses persist over extended periods, a reinsurance or an insurance companys ability to continue as an ongoing concern may be at risk. Therefore, Alleghany views underwriting profit as an important measure in the overall evaluation of performance.