Summary of Significant Accounting Principles (Policies)

9 Months Ended

Sep. 30, 2012

Principles of Financial Statement Presentation

(a) Principles of Financial Statement Presentation

This report should be read in conjunction with the Annual Report on Form 10-K for the year ended December 31, 2011 (the “2011 10-K”) and the Quarterly Reports on Form 10-Q for the quarters ended March 31, 2012 and June 30, 2012 of Alleghany Corporation (“Alleghany”).

Alleghany, a Delaware corporation, which together with its subsidiaries is referred to as “Alleghany” unless the context otherwise requires, is engaged in the property and casualty reinsurance and insurance business. Reinsurance business is conducted through certain subsidiaries of Alleghany’s wholly-owned subsidiary Transatlantic Holdings, Inc. (“Transatlantic”), which was acquired on March 6, 2012 (the “Acquisition Date”) (see Note 2 for additional information on the merger). Insurance business is conducted through certain subsidiaries of Alleghany Insurance Holdings LLC (“AIHL”).

Transatlantic, through its principal wholly-owned subsidiaries, Transatlantic Reinsurance Company (“TRC”), Trans Re Zurich Reinsurance Company Ltd. (“TRZ”) and Fair American Insurance and Reinsurance Company (“FAIRCO”), offers reinsurance capacity to reinsurance and insurance companies for a full range of property and casualty products, through brokers and on a direct basis, in both the domestic and foreign markets. Transatlantic is headquartered in New York with six other locations in the United States and has operations worldwide, including: Bermuda, Canada, seven locations in the United Kingdom and Europe, three locations in Central and South America, and three locations in Asia, Australia, and Africa. One or both of TRC and FAIRCO are licensed, accredited or authorized or can serve as a reinsurer in 50 states and the District of Columbia in the United States and in Puerto Rico and Guam. TRC is also licensed in Bermuda, Canada, Japan, the United Kingdom, the Dominican Republic, the Hong Kong Special Administrative Region of the People’s Republic of China, Germany and Australia. In addition, TRZ is licensed as a reinsurer in Switzerland.

AIHL’s insurance business is conducted through its wholly-owned subsidiaries RSUI Group, Inc. (“RSUI”), Capitol Transamerica Corporation and Platte River Insurance Company (collectively, “CATA”), and Pacific Compensation Corporation (“PCC”).

Alleghany’s equity investments, including those held by Transatlantic’s and AIHL’s operating units, are managed primarily by Alleghany Capital Partners LLC, an indirect, wholly-owned subsidiary of Alleghany. Alleghany also owns and manages properties in the Sacramento, California region through its subsidiary Alleghany Properties Holdings LLC (“Alleghany Properties”). On April 26, 2012, Alleghany’s majority-owned subsidiary BKH Holdings, Inc. acquired Bourn & Koch, Inc. (“Bourn & Koch”), a manufacturer and remanufacturer/retrofitter of precision machine tools and supplier of replacement parts, headquartered in Rockford, Illinois.

In addition, Alleghany owns approximately 33 percent of the outstanding shares of common stock of Homesite Group Incorporated (“Homesite”), a national, full-service, mono-line provider of homeowners insurance, and approximately 38 percent of ORX Exploration, Inc. (“ORX”), a regional oil and gas exploration and production company. These investments are reflected in Alleghany’s financial statements in other invested assets. Alleghany also makes strategic investments in operating companies and conducts other activities at the parent level.

The financial statements contained in this Quarterly Report on Form 10-Q are unaudited, but reflect all adjustments that, in the opinion of management, are necessary for a fair statement of results of the interim periods covered thereby. All adjustments are of a normal and recurring nature except as described herein.

The accompanying unaudited consolidated financial statements include the results of Alleghany and its wholly-owned and majority-owned subsidiaries and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). All significant inter-company balances and transactions have been eliminated in consolidation. The results of Transatlantic are included from the Acquisition Date to September 30, 2012 and not in any prior periods, except with respect to “Supplemental Pro Forma Information” included in Note 2(e), and the results of Bourn & Koch are included from April 26, 2012 to September 30, 2012 and not in any prior periods.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Alleghany relies on historical experience and on various other assumptions that it believes to be reasonable under the circumstances to make judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ materially from those reported results to the extent that those estimates and assumptions prove to be inaccurate. Changes in estimates are reflected in the consolidated statement of earnings and comprehensive income in the period in which the change is made. The results of operations for any interim period are not necessarily indicative of results for the full year.

Investments

(b) Investments

Investments consist of debt securities, equity securities, short-term investments and other invested assets. Alleghany considers all of its marketable equity securities, debt securities and short-term investments as available-for-sale (“AFS”). Debt securities consist of securities with an initial fixed maturity of more than one year. Debt securities typically take the form of bonds. Equity securities generally consist of securities that represent ownership interests in an enterprise. Equity securities typically take the form of common stock. Mutual funds are also classified as equity securities, including funds that invest mostly in debt securities. Short-term investments include commercial paper, certificates of deposit, money market instruments and any fixed maturity investment with an initial maturity of one year or less.

AFS securities are recorded at fair value. Unrealized gains and losses during the year, net of the related tax effect applicable to AFS securities, as well as partnership investments that Alleghany accounts for as AFS, are excluded from earnings and reflected in comprehensive income, and the cumulative effect is reported as a separate component of stockholders’ equity until realized. If a decline in fair value is deemed to be other than temporary, the investment is written down to its carrying value and the amount of the write-down is recorded as an other than temporary impairment (“OTTI”) loss on the statement of earnings. In addition, any portion of such decline that relates to debt securities that is believed to arise from factors other than credit is recorded as a component of other comprehensive income, rather than against earnings.

Other invested assets include invested assets not identified above, primarily related to: (i) equity investments in operating companies where Alleghany has significant influence; (ii) partnership investments (including hedge funds and private equity funds); and (iii) loans receivable. Equity investments in operating companies where Alleghany has significant influence (an aggregate common stock position held at or above 20 percent is presumed to convey significant influence) are accounted for using the equity method. Partnership investments are accounted for as either AFS, or using the equity method where Alleghany has significant influence. Loans receivable are carried at unpaid principal balance.

Net realized gains and losses on investments are determined in accordance with the specific identification method.

Net investment income consists primarily of: (i) interest income from debt securities, short-term investments and cash, including any premium or discount amortization; (ii) dividend income from equity securities; and (iii) investment income from other invested assets, which generally includes distributions when receivable and earnings from investments accounted for under the equity method; less expenses related to investments. Interest income is accrued when earned. Premiums and discounts arising from the purchase of certain debt securities are treated as a yield adjustment over the estimated useful life of the securities, adjusted for anticipated prepayments using the retrospective interest method. Under this method, the effective yield on a security is estimated. Such estimates are based on the prepayment terms of the security, past actual cash flows, and assumptions as to future expected cash flow. The future cash flow assumptions consider various prepayment assumptions based on historical experience, as well as current market conditions. Periodically, the effective yield is re-estimated to reflect actual prepayments and updated future cash flow assumptions. Upon a re-estimation, a security’s book value is restated at the most recently calculated effective yield, assuming that yield had been in effect since the security was purchased. This treatment results in an increase or decrease to net investment income (amortization of premium or discount) at the new measurement date.

See Note 4 for additional information regarding investments.

Fair value

(c) Fair value

Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between willing, able and knowledgeable market participants at the measurement date. Fair value measurements are not adjusted for transaction costs. In addition, a three-tiered hierarchy for inputs is used in management’s determination of fair value of financial instruments that emphasizes the use of observable inputs over the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are market participant assumptions based on market data obtained from sources independent of the reporting entity. Unobservable inputs are the reporting entity’s own assumptions about market participant assumptions based on the best information available under the circumstances. In assessing the appropriateness of using observable inputs in making fair value determinations, Alleghany considers whether the market for a particular security is “active” or not based on all the relevant facts and circumstances. A market may be considered to be inactive if there are relatively few recent transactions or if there is a significant decrease in market volume. Furthermore, Alleghany considers whether observable transactions are “orderly” or not. Alleghany does not consider a transaction to be orderly if there is evidence of a forced liquidation or other distressed condition, and as such, little or no weight is given to that transaction as an indicator of fair value.

Although Alleghany is responsible for the determination of the value of the financial assets and the supporting methodologies and assumptions, it employs third party valuation service providers to gather, analyze and interpret market information and derive fair values based upon relevant methodologies and assumptions for individual instruments. When those providers are unable to obtain sufficient market observable information upon which to estimate the fair value for a particular security, fair value is determined either by requesting a quote, which is generally non-binding, from brokers who are knowledgeable about these securities or by employing widely accepted internal valuation models.

Valuation service providers typically obtain data about market transactions and other key valuation model inputs from multiple sources and, through the use of widely accepted internal valuation models, provide a single fair value measurement for individual securities. The inputs used by the valuation service providers include, but are not limited to, market prices from recently completed transactions and transactions of comparable securities, interest rate yield curves, credit spreads, currency rates, and other market observable information, as applicable. The valuation models take into account, among other things, market observable information as of the measurement date as well as the specific attributes of the security being valued including its term, interest rate, credit rating, industry sector, and when applicable, collateral quality and other issue or issuer specific information. When market transactions or other market observable data is limited, the extent to which judgment is applied in determining fair value is greatly increased.

The hierarchy is broken down into three levels based on the reliability of inputs as follows:

• “Level 1” - Valuations are based on unadjusted quoted prices in active markets that Alleghany has the ability to access for identical, unrestricted assets, and do not involve any meaningful degree of judgment. An active market is defined as a market where transactions for the financial instrument occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Alleghany’s Level 1 assets include publicly traded common stocks and mutual funds where Alleghany’s valuations are based on quoted market prices.

• “Level 2” - Valuations are based on direct and indirect observable inputs other than quoted market prices included in Level 1. Level 2 inputs include quoted prices for similar assets in active markets and inputs other than quoted prices that are observable for the asset, such as the terms of the security and market-based inputs. Terms of the security include coupon, maturity date, and any special provisions that may, for example, enable the investor, at its election, to redeem the security prior to its scheduled maturity date. Market-based inputs include interest rates and yield curves that are observable at commonly quoted intervals and current credit rating(s) of the security. Level 2 assets generally include short-term investments and most debt securities. Alleghany’s Level 2 liabilities consist of the Senior Notes.

• “Level 3” - Valuations are based on techniques that use significant inputs that are unobservable. The valuation of Level 3 assets requires the greatest degree of judgment. These measurements may be made under circumstances in which there is little, if any, market activity for the asset. Alleghany’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment. In making the assessment, Alleghany considers factors specific to the asset. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement is classified is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Some Level 3 valuations are based entirely on non-binding broker quotes. These securities consist primarily of mortgage and asset-backed securities where reliable pool and loan level collateral information cannot be reasonably obtained. Assets classified as Level 3 principally include certain residential mortgage-backed securities (“RMBS”), commercial mortgage-backed securities (“CMBS”), other asset-backed securities, and partnership investments.

Mortgage and asset-backed securities are initially valued at the transaction price. Subsequently, Alleghany uses widely accepted valuation practices that produce a fair value measurement by comparison to transactions in similarly structured instruments, use of discounted cash flows, or option adjusted spread analyses. Unobservable inputs, significant to the measurement and valuation of mortgage and asset-backed securities, include assumptions about prepayment speed and collateral performance, including default, delinquency and loss severity rates. Significant changes to any one of these inputs, or combination of inputs, could significantly change the fair value measurement for these securities.

The impact of prepayment speeds on fair value is dependent on a number of variables including whether the securities were purchased at a premium or discount. A decrease in interest rates generally increases the assumed rate of prepayments, and an increase in interest rates generally decreases the assumed speed of prepayments. Increased prepayments increase the yield on securities purchased at a discount, and reduce the yield on securities purchased at a premium. In a decreasing prepayment environment, yields on securities purchased at a discount are reduced but are increased for securities purchased at a premium. Changes in default assumptions on underlying collateral are generally accompanied by directionally similar changes in other collateral performance factors, but generally result in a directionally opposite change in prepayment assumptions.

Fair values for partnership and private equity investments are initially valued at the transaction price. Subsequently, fair value is based on the performance of the portfolio of investments or results of operations of the investee, as derived from their financial statements. Significant improvements or disruptions in the financial markets may result in directionally similar or opposite changes to the portfolio of the investee, depending on how management of the investee has correlated the portfolio of investments to the market. Also, any changes made by the investee to the investment strategy of the private equity investment could result in significant changes to fair value that have a positive or negative correlation to the performance observed in the equity markets. For those investments whose performance is based on the results of operations within a specific industry, significant events impacting that industry could materially impact fair value. Also, decisions and changes to strategy made by management of the investee could result in positive or negative outcomes, which could significantly impact the results of operations of the investee and subsequently fair value.

Alleghany employs specific control processes to determine the reasonableness of the fair values of its financial assets and liabilities. Alleghany’s processes are designed to ensure that the values received or internally estimated are accurately recorded and that the data inputs and the valuation techniques utilized are appropriate, consistently applied, and that the assumptions are reasonable and consistent with the objective of determining fair value. Alleghany assesses the reasonableness of individual security values received from valuation service providers through various analytical techniques. In addition, Alleghany validates the reasonableness of fair values by comparing information obtained from Alleghany’s valuation service providers to other third party valuation sources for selected securities. Alleghany also validates prices obtained from brokers for selected securities through reviews by those who have relevant expertise and who are independent of those charged with executing investing transactions.

In addition to such procedures, Alleghany reviews the reasonableness of its classification of securities within the three-tiered hierarchy to ensure that the classification is consistent with GAAP.

See Note 3 for additional information regarding fair value.

Cash

(d) Cash

Cash includes all deposit balances with a bank that are available for immediate withdrawal, whether interest-bearing or non-interest bearing.

Premiums and Unearned Premiums

(e) Premiums and Unearned Premiums

Premiums are recognized as revenue on a pro rata basis over the term of an insurance policy. Assumed reinsurance premiums written and earned are based on reports received from ceding companies for pro rata treaty contracts and are generally recorded as written based on contract terms for excess-of-loss treaty contracts. Premiums are earned ratably over the terms of the related coverages.

Unearned premiums and ceded unearned premiums represent the portion of gross premiums written and ceded premiums written, respectively, relating to the unexpired terms of such coverages. Assumed reinsurance premiums written and earned, along with related costs, for which data has not been reported by the ceding companies, are estimated based on historical patterns and other relevant information. These estimates may change when actual data for such estimated items becomes available.

Premium balances receivable are reported net of an allowance for estimated uncollectible premium amounts. Such allowance is based upon an ongoing review of amounts outstanding, length of collection periods, the creditworthiness of the insured, and other relevant factors. Amounts deemed to be uncollectible are written off against the allowance.

Reinsurance Ceded

(f) Reinsurance Ceded

Reinsurance is used to mitigate the exposure to losses, manage capacity and protect capital resources. Reinsuring loss exposures does not relieve a ceding entity from its obligations to policyholders. Reinsurance recoverables (including amounts related to claims incurred but not reported) and ceded unearned premiums are reported as assets. To minimize exposure to losses from a reinsurer’s inability to pay, the financial condition of such reinsurer is evaluated initially upon placement of the reinsurance and periodically thereafter. In addition to considering the financial condition of a reinsurer, the collectibility of the reinsurance recoverables is evaluated (and where appropriate, whether an allowance for estimated uncollectible reinsurance recoverables is to be established), based upon a number of other factors. Such factors include the amounts outstanding, length of collection periods, disputes, any collateral or letters of credit held, and other relevant factors. To the extent that an allowance for uncollectible reinsurance recoverable is established, amounts deemed to be uncollectible are written off against the allowance for estimated uncollectible reinsurance recoverables. Alleghany currently has no allowance for uncollectible reinsurance recoverables. See Note 5 for additional information on reinsurance ceded.

Ceded premiums written are recorded in accordance with the applicable terms of the various reinsurance contracts, and ceded premiums earned are charged against revenue over the period of the various reinsurance contracts. This also generally applies to reinstatement premiums paid to a reinsurer, which arise when contractually-specified ceded loss triggers have been breached. Ceded commissions reduce commissions, brokerage and other underwriting expenses, and ceded losses incurred reduce net loss and loss adjustment expense (“LAE”) incurred over the applicable periods of the various reinsurance contracts with third party reinsurers. If premiums or commissions are subject to adjustment (for example, retrospectively-rated or experience-rated), the estimated ultimate premium or commission is recognized over the period of the contract.

Amounts recoverable from reinsurers are estimated in a manner consistent with the claim liability associated with the reinsured business and consistent with the terms of the underlying reinsurance contract.

Deferred Acquisition Costs

(g) Deferred Acquisition Costs

As discussed in more detail in Note 1(q), Alleghany adopted new accounting guidance in the first quarter of 2012 related to acquisition costs.

Acquisition costs related to unearned premiums that vary with, and are directly related to, the production of such premiums are deferred. Furthermore, such deferred costs: (i) represent only incremental, direct costs associated with the successful acquisition of a new or renewal insurance or reinsurance contract; (ii) are essential to the contract transaction; (iii) would not have been incurred had the contract transaction not occurred; and (iv) are related directly to the acquisition activities involving underwriting, policy issuance and processing. Acquisition costs principally relate to commissions. To a lesser extent, acquisition costs can include premium taxes and certain qualifying underwriting expenses. For insurance policies written, acquisition costs are generally incurred directly, and include commissions, premium taxes and certain qualifying underwriting expenses. For reinsurance contracts written, acquisition costs are generally incurred through brokerage commissions and indirectly through ceding commissions, which are deferred. Deferred acquisition costs are amortized to expense as the related premiums are earned, generally over a period of one year. Deferred acquisition costs are reviewed at least annually to determine their recoverability from future income, including investment income. If any such costs are determined not to be recoverable they are charged to expense.

Anticipated net loss and LAE and estimated remaining costs of servicing the contracts are considered when evaluating recoverability of deferred acquisition costs.

Property and Equipment

(h) Property and Equipment

Property and equipment is carried at cost, net of accumulated depreciation and amortization. Depreciation of buildings and equipment is principally calculated using the straight-line method over the estimated useful life of the respective assets. Estimated useful lives for such assets range from 3 to 20 years. Amortization of leasehold improvements is principally calculated using the straight-line method over the estimated useful life of the leasehold improvement or the life of the lease, whichever is less. Rental expense on operating leases is recorded on a straight-line basis over the term of the lease, regardless of the timing of actual lease payments.

Goodwill and Other Intangible Assets

(i) Goodwill and Other Intangible Assets

Goodwill and other intangible assets, net of amortization, are recorded as a consequence of business acquisitions. Goodwill represents the excess, if any, of the amount paid to acquire subsidiaries and other businesses over the fair value of their net assets at the date of acquisition. Other intangible assets are recorded at their fair value as of the acquisition date. A significant amount of judgment is needed to determine the fair values at the date of acquisition of other intangible assets and the net assets acquired in a business acquisition. The determination of the fair value of other intangible assets and net assets often involves the use of valuation models and other estimates, which involve many assumptions and variables and are inherently subjective. Other intangible assets that are not deemed to have an indefinite useful life are amortized over their estimated useful lives. Goodwill and those intangible assets that have an indefinite useful life are not subject to amortization.

Goodwill and other intangible assets deemed to have an indefinite useful life are tested annually in the fourth quarter of every year for impairment. Goodwill and other intangible assets are also tested whenever events and changes in circumstances suggest that the carrying amount may not be recoverable. A significant amount of judgment is required in performing goodwill and other intangible asset impairment tests. These tests include estimating the fair value of Alleghany’s operating units and other intangible assets. If it is determined that an asset has been impaired, the asset is written down by the amount of the impairment, with a corresponding charge to net earnings. Subsequent reversal of any impairment charge is not permitted.

With respect to goodwill, a qualitative assessment is first made to determine whether it is necessary to perform quantitative testing. This initial assessment includes, among others, consideration of: (i) past, current and projected future earnings and equity; (ii) recent trends and market conditions; and (iii) valuation metrics involving similar companies that are publicly-traded and acquisitions of similar companies, if available. If this initial qualitative assessment indicates that the fair value of an operating unit may be less than its respective carrying amount, a second step is taken, involving a comparison between the estimated fair values of the operating units with their respective carrying amounts including goodwill. Under GAAP, fair value refers to the amount for which the entire operating unit may be bought or sold. The methods for estimating operating unit values include asset and liability fair values and other valuation techniques, such as discounted cash flows and multiples of earnings or revenues. All of these methods involve significant estimates and assumptions. If the carrying value exceeds estimated fair value, there is an indication of potential impairment, and a third step is performed to measure the amount of impairment. The third step involves calculating an implied fair value of goodwill by measuring the excess of the estimated fair value of the operating units over the aggregate estimated fair values of the individual assets less liabilities. If the carrying value of goodwill exceeds the implied fair value of goodwill, an impairment charge is recorded for the excess.

See Note 1(q) and Note 2 for additional information on goodwill and other intangible assets.

Income Taxes

(j) Income Taxes

Alleghany files a consolidated federal income tax return with its subsidiaries. Following the Acquisition Date, Alleghany’s consolidated federal income tax return will include as part of its taxable income those items of income of non-U.S. subsidiaries that are subject to U.S. income tax currently, pursuant to Subpart F income rules of the Internal Revenue Code. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Current tax liabilities or assets are recognized for the estimated taxes payable or refundable on tax returns for the current year.

A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized. This determination is based upon a review of all available evidence, both positive and negative, including Alleghany’s earnings history, the timing, character and amount of future earnings potential, the reversal of taxable temporary differences and the tax planning strategies available.

See Note 9 for additional information on income taxes.

Loss Reserves

(k) Loss Reserves

The reserves for loss and LAE represent management’s best estimate of the ultimate cost of all reported and unreported losses incurred through the balance sheet date.

The reserves for loss and LAE include but are not limited to: (i) reports and individual case estimates received from ceding companies, with respect to assumed reinsurance business; (ii) the accumulation of individual estimates for claims reported, with respect to direct insurance business; (iii) estimates for incurred but not reported (“IBNR”) claims based on past experience, modified for current trends and industry data; and (iv) estimates of expenses for investigating and settling claims based on past experience. The methods used to determine such estimates and to establish the resulting reserves are continually reviewed and updated. Any adjustments are reflected in current income. Net loss and LAE incurred consists of the estimated ultimate cost of settling claims incurred within the reporting period (net of related reinsurance recoverable), including IBNR claims, plus changes in estimates of prior period losses.

The estimation of loss reserves is inherently difficult and subjective, especially in view of changing legal and economic environments that impact the development of loss reserves. Therefore, quantitative techniques have to be supplemented by subjective considerations and managerial judgment. In addition, trends that have affected development of liabilities in the past may not necessarily occur or affect liability development to the same degree in the future.

Although the reserving process is difficult for insurance companies, the inherent uncertainties of estimating loss reserves are even greater for reinsurers, due primarily to a lag in claims reporting, the longer-term nature of much of the reinsurance business, the diversity of development patterns among different types of reinsurance treaties or facultative contracts, the necessary reliance on the ceding companies for information regarding reported claims, and differing reserving practices among ceding companies, which may change without notice. Alleghany writes a significant amount of non-proportional assumed casualty reinsurance as well as proportional assumed reinsurance of excess liability business for classes such as medical malpractice, directors and officers (“D&O”) liability, errors and omissions liability and general casualty. Claims from such classes can exhibit greater volatility over time than most other classes due to their low frequency, high severity nature and loss cost trends that are more difficult to predict. Net loss and LAE also include amounts for risks relating to asbestos-related illnesses and environmental impairment. See Notes 6 and 12(d) for additional information on loss reserves.

Earnings Per Share of Common Stock

(l) Earnings Per Share of Common Stock

Basic earnings per share of common stock is based on the average number of shares of common stock, par value $1.00 per share, of Alleghany (“Common Stock”) outstanding during the period, retroactively adjusted for stock dividends. Diluted earnings per share of Common Stock are based on those shares used to calculate basic earnings per share of Common Stock plus the dilutive effect of stock-based compensation awards, retroactively adjusted for stock dividends. See Note 11 for additional information on earnings per share.

Stock-Based Compensation Plans

(m) Stock-Based Compensation Plans

The cost resulting from all stock-based compensation transactions is recognized in the financial statements, with fair value as the measurement objective in accounting for stock-based compensation arrangements. The fair value-based measurement method applies in accounting for stock-based compensation transactions with employees. Non-employee directors are treated as employees for accounting purposes.

With respect to stock option grants, the fair value of each option award is estimated on the date of grant using the Black-Scholes option pricing model. Expected volatilities are based on historical volatility of the Common Stock. Alleghany uses historical data to estimate option exercise and employee termination within the valuation model. The expected term of options granted is derived from the output of the option valuation model and represents the period of time that options granted are expected to be outstanding. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant.

Senior Notes

(n) Senior Notes

Debt consists of senior notes issued by Alleghany (the “Alleghany Senior Notes”) and senior notes issued by Transatlantic (the “Transatlantic Senior Notes,” and collectively with the Alleghany Senior Notes, the “Senior Notes”). The Senior Notes are carried at unpaid principal balance including any unamortized premium or discount.

See Note 8 for additional information on the Senior Notes.

Currency Translation

(o) Currency Translation

Assets and liabilities denominated in foreign currencies are translated into U.S. dollars at period-end exchange rates. Income and expense accounts are translated at average exchange rates for the year. The resulting unrealized currency translation gain (loss) for functional currencies is recorded, net of tax, in accumulated other comprehensive income, a component of stockholders’ equity.

Transaction gains and losses on assets and liabilities denominated in foreign currencies are recorded as a component of net realized capital gains (losses) during the period in which they occur.

Reclassification

(p) Reclassification

Certain prior year amounts have been reclassified to conform to the 2012 presentation of the financial statements.

Recent Accounting Standards

(q) Recent Accounting Standards

Recently Adopted

In September 2011, the Financial Accounting Standards Board (the “FASB”) issued revised guidance on the testing of goodwill for impairment. This guidance simplifies how an entity tests goodwill for impairment by allowing an entity to first make a qualitative assessment to determine whether it is necessary to perform quantitative testing. Based on the results of such assessment, an entity will no longer be required to perform quantitative testing if it is more likely than not that the fair value of a reporting unit is greater than its carrying value. This guidance is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011, with early adoption permitted. Alleghany adopted this guidance in the first quarter of 2012, and the implementation did not have an impact on its results of operations and financial condition.

In June 2011, the FASB issued guidance on the presentation of comprehensive income. This guidance, as amended in December 2011, increases the prominence of other comprehensive income in the financial statements and eliminates the current option to report other comprehensive income and its components in the statement of changes in equity. This guidance does not change the items that must be reported within other comprehensive income. This guidance is generally effective for interim and annual periods beginning after December 15, 2011. Alleghany adopted this guidance in the first quarter of 2012, and the implementation did not have an impact on its results of operations and financial condition.

In May 2011, the FASB issued guidance that addresses requirements for measuring fair value. Among other things, the guidance clarifies that the “highest and best use” valuation premise applies only to non-financial assets, and that premiums or discounts should be applied to valuations of an individual asset or liability only when market participants would do so. The guidance also permits measurement of fair value of financial instruments (that are carried at fair value) based on an entity’s net exposure to a particular market or credit risk on a net basis if there is evidence that the entity manages its financial instruments in this way. The guidance provides for additional financial statement disclosure regarding fair value measurements, including disclosure involving transfers between categories within the fair value hierarchy, and quantitative and qualitative information about fair value measurements that involve a significant degree of judgment. This guidance is effective for interim and annual periods ending after December 15, 2011. Alleghany adopted this guidance in the first quarter of 2012, and the implementation did not have a material impact on its results of operations and financial condition.

In October 2010, the FASB issued guidance that provides additional clarification for costs associated with acquiring or renewing insurance contracts. This guidance states that only incremental, direct costs associated with the successful acquisition of a new or renewal insurance contract may be capitalized as deferred acquisition costs. Furthermore, such costs: (i) must be essential to the contract transaction; (ii) would not have been incurred had the contract transaction not occurred; and (iii) must be related directly to the acquisition activities involving underwriting, policy issuance and processing, medical and inspection, and sales force contract selling. Advertising costs should be included in deferred acquisition costs only if the capitalization criteria in separate “direct response” advertising guidance within GAAP are met. All other acquisition-related costs and other expenses should be charged to expense as incurred. This guidance is effective for interim and annual periods beginning after December 15, 2011, with early adoption permitted. Alleghany adopted this guidance in the first quarter of 2012, and the implementation did not have a material impact on its results of operations and financial condition.

Future Application of Accounting Standards

In July 2012, the FASB issued revised guidance on the testing of certain intangible assets for impairment. This guidance simplifies how an entity tests for impairment of intangible assets other than goodwill, such as licenses and trade names, that are determined to have an indefinite life. The revised guidance allows an entity to first make a qualitative assessment to determine whether it is necessary to perform quantitative testing. Based on the results of such assessment, an entity will only be required to perform quantitative testing if it is more likely than not that the asset is impaired. This guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012, with early adoption permitted. Alleghany will adopt this guidance in the fourth quarter of 2012, and Alleghany currently does not believe that the implementation will have a material impact on its results of operations and financial condition.

In December 2011, the FASB issued guidance on disclosure requirements related to offsetting arrangements. The guidance provides for additional financial statement disclosure regarding offsetting and related arrangements to enable financial statement users to understand the effect of those arrangements on an entity’s financial position. This guidance is effective for interim and annual reporting periods beginning on or after January 1, 2013. Alleghany will adopt this guidance in the first quarter of 2013, and Alleghany currently does not believe that the implementation will have a material impact on its results of operations and financial condition.