Reserve Roll-Forward

The following table presents a reconciliation of our beginning and ending gross reserve for losses and loss expenses and net reserve for unpaid losses and loss expenses for the periods indicated:




Nine months ended September 30,	2017			2016

Gross reserve for losses and loss expenses, beginning of period	$	9,697,827		$	9,646,285
Less reinsurance recoverable on unpaid losses, beginning of period	(2,276,109		)	(2,031,309		)
Net reserve for unpaid losses and loss expenses, beginning of period	7,421,718			7,614,976

Net incurred losses and loss expenses related to:
Current year	2,591,135			1,887,715
Prior years	(143,495		)	(224,131		)
	2,447,640			1,663,584
Net paid losses and loss expenses related to:
Current year	(328,751		)	(233,124		)
Prior years	(1,384,510		)	(1,334,772		)
	(1,713,261		)	(1,567,896		)

Foreign exchange and other	333,456			(112,649		)

Net reserve for unpaid losses and loss expenses, end of period	8,489,553			7,598,015
Reinsurance recoverable on unpaid losses, end of period	2,298,022			2,276,792
Gross reserve for losses and loss expenses, end of period	$	10,787,575		$	9,874,807

We write business with loss experience generally characterized as low frequency and high severity in nature, which can result in volatility in our financial results. During the nine months ended September 30, 2017 and 2016, we recognized aggregate net losses and loss expenses, net of reinstatement premiums of $702 million and $145 million, respectively, in relation to catastrophe and weather related events.

The transfer of the insurance business of AXIS Specialty Australia to a reinsurer was approved by the Irish High Court on February 1, 2017 and the Federal Court of Australia on February 10, 2017. Consequently, the insurance policies, assets and liabilities of AXIS Specialty Australia were transferred to the reinsurer with effect from February 13, 2017. This resulted in the reduction of reserves for losses and loss expenses by $223 million and a reduction in reinsurance recoverables on unpaid and paid losses by $223 million.

On April 1, 2017, the Company acquired a 100% ownership interest in Aviabel. Foreign exchange and other includes reserves for losses and loss expenses of $79 million and reinsurance recoverables on unpaid and paid losses of $5 million related to this acquisition.

Prior Year Development

Prior year reserve development arises from changes to loss and loss expense estimates related to losses incurred in previous calendar years. Such development is summarized by segment in the following table:



	Three months ended September 30,				Nine months ended September 30,
	2017		2016		2017		2016

Insurance	$	2,603	$	20,688	$	30,740	$	43,181
Reinsurance	45,165		55,331		112,755		180,950
Total	$	47,768	$	76,019	$	143,495	$	224,131

Net favorable prior year reserve development for the three months ended September 30, 2017 included significant contributions from our medium and long tail reserve classes. Net favorable prior year reserve development for the nine months ended September 30, 2017 included significant contributions from short, medium, and long tail reserve classes. Net favorable prior year reserve development for the three and nine months ended September 30, 2016 included significant contributions from our short and long tail reserve classes.

Our short tail business includes the underlying exposures in our property and other, marine and aviation reserve classes within our insurance segment, and the property and other reserve class within our reinsurance segment. Development from these classes contributed $5 million and $41 million of net favorable prior year reserve development for the three and nine months ended September 30, 2017, respectively. These short-tail lines contributed $41 million and $116 million of net favorable prior year reserve development for the three and nine months ended September 30, 2016, respectively. The net favorable development for these classes primarily reflected the recognition of better than expected loss emergence.

Our medium-tail business consists primarily of professional insurance and reinsurance reserve classes, credit and political risk insurance reserve class, and credit and surety reinsurance reserve class. For the three months ended September 30, 2017, the professional reinsurance reserve class contributed net favorable prior year reserve development of $9 million. For the nine months ended September 30, 2017, the professional insurance and reinsurance reserve class contributed net favorable prior year reserve development of $54 million. For the three and nine months ended September 30, 2017, the credit and surety reinsurance reserve class recorded net favorable prior year development of $17 million and $18 million, respectively. This net favorable prior year reserve development reflected the recognition of generally better than expected loss emergence. For the three and nine months ended September 30, 2016, the professional reserve classes contributed net favorable prior year reserve development of $12 million and $28 million, respectively. The net favorable prior year reserve development on these reserve classes reflected generally favorable experience as we continued to transition to more experience based methods.

Our long-tail business consists primarily of liability and motor reserve classes. For the nine months ended September 30, 2017, the liability reinsurance reserve class contributed net favorable prior year reserve development of $40 million. For the three and nine months ended and September 30, 2016, the liability reinsurance reserve class contributed net favorable prior year development of $10 million and $32 million, respectively. The net favorable prior year reserve development for our liability reinsurance reserve class in both years primarily reflected the progressively increased weight given by management to experience based indications on older accident years, which has generally been favorable. For the nine months ended September 30, 2017, the liability insurance reserve class recorded net adverse prior year reserve development of $6 million, primarily attributable to reserve strengthening within our run-off Bermuda excess casualty book of business.

For the three and nine months ended September 30, 2017, the motor reinsurance reserve class recorded net favorable prior year development of $16 million and net adverse prior year reserve development of $4 million, respectively. For the three months ended September 30, 2017, the net favorable prior year reserve development related to favorable loss emergence trends on several classes of business spanning multiple accident years. For the nine months ended, the net adverse prior year development was driven by the U.K. Ministry of Justice’s recent announcement of a decrease in the discount rate used to calculate lump sum awards in U.K. bodily injury cases, known as the Ogden rate. Effective March 20, 2017, the Ogden rate changed from plus 2.5% to minus 0.75%. For the three and nine months ended September 30, 2016, the motor reinsurance reserve class contributed $7 million and $40 million, respectively, of net favorable prior year reserve development related to favorable loss emergence trends on several classes of business spanning multiple accident years.

Our September 30, 2017 net reserves for losses and loss expenses includes estimated amounts for numerous catastrophe events. We caution that the magnitude and/or complexity of losses arising from certain of these events, in particular Hurricanes Harvey, Irma and Maria and the two earthquakes in Mexico, as well as Hurricane Matthew, the Fort McMurray wildfires, Storm Sandy, the 2011 Japanese earthquake and tsunami, the 2010-11 New Zealand earthquakes and the Tianjin port explosion, inherently increases the level of uncertainty and, therefore, the level of management judgment involved in arriving at our estimated net reserves for losses and loss expenses. As a result, our actual losses for these events may ultimately differ materially from our current estimates.