How many {published in} are to/by {The Economist} ?
How many articles are in The Economist?
How many publications are published in The Economist?
SELECT ( COUNT ( ?c ) AS ?h ) { ?c property:published_in resource:The_Economist }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1433> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q180089 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1433 wd:Q180089 }
57