Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_19948664_1 ( countries_sampled VARCHAR, ranking_la__2_ VARCHAR, world_ranking__1_ VARCHAR )

### Question ###
How many countries were sampled for the index in 2nd place in the LA ranking and 23rd in the world ranking?

### Accurate SQL ###

SELECT countries_sampled FROM table_19948664_1 WHERE ranking_la__2_ = "2nd" AND world_ranking__1_ = "23rd"