Currency vs Unit of Measure

[Leigh Dodds]

Hi,

I notice that there is an SDMX attribute for Currency as well as Unit of Measure.

If I'm expressing, say, GDP values and want to state that the observations are in USD is it better to use the currency attribute or just record it as a unit of measure?

Regardless of the attribute, it looks like a good value for the property is:

http://qudt.org/vocab/unit#USDollar

Cheers,

L.

[Dave Reynolds]

On 10/10/12 12:58, Leigh Dodds wrote:
> Hi,
>
> I notice that there is an SDMX attribute for Currency as well as Unit of
> Measure.

Yes, odd isn't it.

The RDF version is just a clone of the COG [1].

I suspect one use of the currency concept is when you want to use it for
dimensions (e.g. for a table of historic conversion rates between
different currencies). However the COG description allows use as a
unit-of-measure.

> If I'm expressing, say, GDP values and want to state that the
> observations are in USD is it better to use the currency attribute or
> just record it as a unit of measure?

I think either is OK. I have a preference[2] for unit of measure because
that seems like the more general pattern. The COG description of
UNIT_MEAUSRE explicitly gives currency as an example so you are
definitely safe using that.

Dave

[1]
http://sdmx.org/wp-content/uploads/2009/01/01_sdmx_cog_annex_1_cdc_2009.pdf

[2] For the payments ontology we create a specific property and then
linked it to the sdmx-concept of currency, but that's because currency
was such a central aspect of payments that everyone wanted it explicit
in the ontology.

[A. Gregory]

Folks:

Dave is right - when currency is used as a unit of measure, it should be a unit of measure. Currencies also play other roles, hence the duplication in the COG.

Cheers,

Arofan Gregory

[Sarven Capadisli]

On 2012-10-10 14:53, Dave Reynolds wrote:
> On 10/10/12 12:58, Leigh Dodds wrote:
>> Hi,
>>
>> I notice that there is an SDMX attribute for Currency as well as Unit of
>> Measure.
>
> Yes, odd isn't it.
>
> The RDF version is just a clone of the COG [1].
>
> I suspect one use of the currency concept is when you want to use it for
> dimensions (e.g. for a table of historic conversion rates between
> different currencies).

This is it.

However the COG description allows use as a
> unit-of-measure.
>
>> If I'm expressing, say, GDP values and want to state that the
>> observations are in USD is it better to use the currency attribute or
>> just record it as a unit of measure?
>
> I think either is OK. I have a preference[2] for unit of measure because
> that seems like the more general pattern. The COG description of
> UNIT_MEAUSRE explicitly gives currency as an example so you are
> definitely safe using that.
>
> Dave
>
> [1]
> http://sdmx.org/wp-content/uploads/2009/01/01_sdmx_cog_annex_1_cdc_2009.pdf
>
> [2] For the payments ontology we create a specific property and then
> linked it to the sdmx-concept of currency, but that's because currency
> was such a central aspect of payments that everyone wanted it explicit
> in the ontology.
>
>

I ran into this myself and for WB Finances datasets decided to go with
UNIT_MEASURE as well. I've created:

property:currency
a qb:AttributeProperty ;
rdfs:subPropertyOf sdmx-attribute:unitMeasure .

and the accompanying:

classification:currency
a skos:ConceptScheme .

-Sarven