.. index:: QS, Financial Structures; QS, Quota Share

Quota Share (QS)
==================================

Graphene provides a default built-in template for modelling conventional
Quota Share (QS) contracts. The default template for
QS supports the following financial features:

- occurrence limit
- upfront premium income and brokerage expense
- contract inception / expiration dates
- participation
- currency exchange

Structure
---------

The general structure of a default QS using the built-in template in
Graphene is:

.. code-block:: json

    {
        "_schema": "QuotaShare_1.0",
        "inception_date": 1546300800,
        "expiration_date": 1577836800,
        "limit_value": 30000.0,
        "premium_value": 3000.0,
        "brokerage": 0.1,
        "share": 0.2,
        "currency": "GBP"
    }

Parameters
----------

The parameters are defined as follows:

+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
|           Parameter Name | Required |    Type    |                                                                                                 Description                                                           |
+==========================+==========+============+=======================================================================================================================================================================+
| ``inception_date``       | Yes      | ``double`` | Timestamp on which the contract incepts. The coverage period is **inclusive** of this time. See :ref:`ledger-format` for more details on timestamps.                  |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``expiration_date``      | Yes      | ``double`` | Timestamp on which the contract expires. The coverage period is **exclusive** of this time. See :ref:`ledger-format` for more details on timestamps.                  |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``limit_value``          | Yes      | ``double`` | The occurrence limit of the contract in currency units.                                                                                                               |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``premium_value``        | Yes      | ``double`` | The amount of premium paid upfront in currency units. Premium is paid at time of inception.                                                                           |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``brokerage``            | Yes      | ``double`` | The percentage of brokerage paid on the upfront premium. Brokerage is paid at time of inception.                                                                      |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``share``                | Yes      | ``double`` | The share or participation assumed for this contract.                                                                                                                 |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``currency``             | No       | ``string`` | The currency in which the input currency values (``limit_value`` and ``premium_value``) are defined. Defaults to the :ref:`base currency <base-currency>` if not set. |
+--------------------------+----------+------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Output Records
--------------

The QS financial structure can produce 5 different types of records:

- ``Loss``: Layered losses, that is losses that are covered by the contract.
  Losses generally have a negative value.
- ``Premium``: Upfront premium paid at
  the time of inception. Premium is accounted for as a positive credit.
- ``BrokerageFee``: Upfront premium brokerage paid at the time of inception.
  Brokerage is accounted as an expense debit with a negative value.

References
----------

A detailed description of the financial modelling internals of the QS
structure can be found in :doc:`quotashare_step_by_step`.