27 



to a given resultant, while at the same time one of them bears a 

 causal relation to the other, unless the effect of one of them is 

 entirely known it is necessary to devise some means of eliminating 

 the effect of one of them before the effect of the other can be deter- 

 mined. When the number of farms is sufficiently large the effect 

 of one of two related causal factors may sometimes be eliminated 

 by limiting the investigation to farms on which there is little or 

 no variation in that factor. Thus, in studying the relation of size 

 of farm to labor income, the confusing influence of size of farm on 

 intensity of the type of farming may be eliminated by confining 

 the study to types of farming comparable in intensiveness. 



CLASSIFICATION BY TENURE. 



Before undertaking comparative studies of a group of farms they 

 must be separated into classes in which all farms in each class are 

 comparable. The first separation should be based on tenure, and 

 may include the following classes: 



1. Plantations (to be considered elsewhere). 



2. Manager farms; those operated by a hired manager. 



3. Working owner farms; those operated by owners who take 

 the part of a working manager without salary. 



4. Nonworking owner farms; those operated by owners who direct 

 but take no part in the work of the farm. 



5. Owner and landlord farms; those, part of which is operated by 

 the owner, the remainder being rented out. 



6. Owner and tenant farms; those operated as in (3), but of which 

 the operator owns only part of the land, holding the remainder 

 as a tenant. 



7. Cash tenant farms; farms rented for cash and operated by 

 the tenant as a working manager without salary, the working 

 capital being furnished by the tenant. 



8. Share tenant farms; those operated as in (7), but with rent 

 consisting of a share of the proceeds. 



9. Tenant laborer (or cropper) farms; tenant farms on which the 

 tenant furnishes little or none of the working capital. 



10. Combined tenant farms; two or more farms operated by one 

 tenant, but rented from different landlords, or on a different basis. 



