Economic theory states that immigrants learn English as long as incentives exist to do so. One such incentive is greater labor income, such as hourly wages. Studies consistently find a positive correlation between an immigrant's earnings and his English ability. Thus, while there are economic incentives to learning English, the fact remains that learning English is not a costless endeavor. Furthermore, English is not a unidimensional characteristic.
English proficiency encompasses such abilities as speaking, understanding, reading, and writing.
The bulk of studies that examine either the economic gains to learning English or the acquisition of English have been limited to speaking ability only. This is due to the scant information available in the Census and Current Population Surveys, which are the data sources for the majority of studies. Other studies that attempt to remedy this shortcoming examine one or more English skills, but their drawback is in the small sample sizes, or the unrepresentative nature of the data used. In 1992, however, the National Center for Education Statistics conducted one of the most comprehensive literacy surveys of the nation's adult population, the National Adult Literacy Survey. I then identify which of these skills is associated with greater income.