For the first time in our history, Assured Guaranty's adjusted book value has surpassed $100 per share and both shareholders' equity per share and adjusted operating shareholders' equity per share were also new records.
We achieved this milestone while producing our best direct new business insurance production for second quarter since the acquisition of AGM in July of 2009.
Our financial guaranty, guaranty PVP of $96 million was 71% higher than in last year's second quarter.
Our people were extremely effective, operating 100% remotely in unprecedented economic and market conditions.
As a result, we saw the best second quarter and first half direct U.S. public finance production in more than a decade, driving direct PVP of $60 million and $89 million, respectively.
And I can tell you that with our July municipal insured par volume exceeding $2 billion, the surge in demand for our guaranty has not let up.
At the industry level, more than $9.1 billion of U.S. public finance primary market par was sold with bond insurance in the second quarter, the most for any quarter since mid-2009 and industry insurance penetration reached 8.7% of total new issue par sold, the highest quarterly level since 2009.
Six months industry insured volume is 43% higher than in the first six months of 2019.
In this strengthened municipal bond insurance market, Assured Guaranty was selected to ensure 63% of the insured new issue par sold in the second quarter.
Compared with the second quarter of last year, Assured Guaranty's primary market production was up 58% to $5.8 billion in insured par sold and up 22% to 318 new issue in transaction count.
We guaranteed 11 transactions of over $100 million in insured par during the quarter, the largest of which was a $385 million school district transaction with the dormitory authority of the state of New York, rated double AA3 by Moody's and AA minus by Fitch.
The high value that investors place in our guaranty was visible among credits with underlying S&P or Moody's ratings in the AA category, where we insured more than $1 billion of primary market par in the second quarter.
During the second quarter, we insured $533 million of secondary market par compared with $233 million for the first quarter of the year and $327 million for the second quarter of 2019.
In aggregate for the primary and secondary markets, Assured Guaranty provided insurance on $6.3 billion of municipal bonds, 58% more than in last year's second quarter.
We also had a great second quarter in our international infrastructure business, where we generated $28 million of direct PVP, over 3 times last year's second quarter PVP and the second highest quarterly direct PVP in the sector, since before the Great Recession.
Our global structured finance business also performed well in the second quarter contributing $8 million of PVP from a variety of transactions, including an insurance securitization and two whole business securitizations.
We continue to believe that for the remainder of the portfolio, the 96% of par exposure that is investment grade, there should be no material losses caused by the pandemic.
For example from 2008 through second quarter 2020, we paid $11 billion in gross claims, $5 billion in net and returned more than $4.3 billion to shareholders through share repurchases and dividends.
We estimate that we have $2.6 billion of capital in excess of S&P's AAA requirement as of year-end 2019.
We continue to support the growth of the business and have allocated $1 billion of our investment portfolio to investment it manages, with the goal of generating even greater value for our investors and policyholder.
As we worked with David for a long time has over 30 years of experience includes senior positions at ACE Financial Solutions, which required Capital Re when David was its CFO and which is a company we now know as Assured Guaranty Corp.
We have abundant capital liquidity, supporting a 96% investment grade insured portfolio, consisting of transactions carefully selected to perform better under economic stress than others in their respective sectors.
In terms of capital management, we are ahead of our plan, relative to the number of shares repurchased, which helped us to propel our adjusted book value per share to over $100, a record high.
Turning to second quarter 2020, adjusted operating income was strong coming in at $190 million or $1.36 per share.
This consists of $154 million of income from our Insurance segment, a $9 million loss from our Asset Management segment and a $26 million loss from our Corporate division, which is where we reflect our holding company interest and other corporate expenses.
Starting with the Insurance segment, adjusted operating income was $154 million compared to $161 million in the second quarter of 2019.
Net earned premiums and credit derivative revenues in the second quarter 2020 were $125 million compared with $127 million in the second quarter of 2019.
Structured finance net earned premiums and credit-driven revenues decreased to total of $13 million, due to the decline in this portfolio.
In total, accelerations due to refundings and terminations were $32 million in the second quarter 2020 compared with $29 million in the second quarter of 2019.
This reassumption resulted in the $30 million -- $38 million commutation gain.
Net investment income for the Insurance segment was $82 million in the second quarter of 2020 compared with $110 million in the second quarter of 2019.
Second quarter 2020 Insurance segment adjusted operating income also includes a $21 million after-tax mark-to-market gain on our investments in Assured Investment Management funds.
As of June 30, 2020, the insurance companies had authorization to invest up to $500 million in funds managed by Assured Investment Management, of which $354 million have been invested as of June 30, 2020.
Loss expense in the Insurance segment was $39 million in the second quarter of 2020 and was primarily related to economic loss development on certain Puerto Rico exposures.
In the second quarter of 2019, we recorded a benefit of $50 million primarily related to higher projected recoveries for previously charged up loans for second lien U.S. RMBS.
The net economic development in the second quarter 2020 was $34 million, which primarily consisted of loss development of $30 million in the U.S. public finance sector, primarily attributable to Puerto Rico exposures.
Net economic loss development in U.S. RMBS of $1 million mainly consisted of increased delinquencies, offset by higher projected excess spread across both third and second lien transactions.
In the Asset Management segment, adjusted operating income was a loss of $9 million.
Prior to the current market disruptions, we had made good progress on the winding down of legacy funds, with outflows of $541 million in the second quarter.
As of June 30, 2020, the insurance subsidiaries have together allocated $250 million to the municipal obligation strategies and $100 million to CLO strategies, with authorization to allocate an additional $200 million to CLO strategies.
In our Corporate division, the holding companies currently have cash and investment available for liquidity needs in capital management activities of approximately $70 million, of which $80 million resides in AGL.
Adjusted operating loss for the Corporate division was a loss of $26 million in both second quarter 2020 and second quarter 2019.
In second quarter 2020, the effective tax rate was 14.2%, compared with 21% in the second quarter of 2019.
Turning to our capital management strategy, in the second quarter of 2020, we repurchased 6 million shares for $164 million, for an average price of $27.49 per share.
Since the end of the quarter, we have purchased an additional 800,000 shares for $90 million, bringing our year-to-date repurchases as of today to over 10 million shares.
Since January 2013, our successful capital management program has returned $3.5 billion to shareholders, resulting in a 60% reduction in total shares outstanding.
The cumulative effect of these repurchases was a benefit of approximately $23.56 per share in adjusted operating shareholders' equity and approximately $42.76 in adjusted book value per share, which helped drive these important metrics to new record highs of $71.34 in adjusted operating shareholders' equity per share and $104.63 of adjusted book value per share, which both represent record high.

Summary:
Turning to second quarter 2020, adjusted operating income was strong coming in at $190 million or $1.36 per share.