Identifying useful analytical concepts in literature review: an example

 Identifying useful analytical concepts [including theories] in literature review: an example:

Information mentioned in the academic literature [for example]:

Empirical observation 1:

Longer period of lockdown in Singapore  ----> lower birth rate in Singapore

Empirical observation 2: 

Longer period of lockdown in the Philippines  ----> higher birth rate in the Philippines

For literature review, it is not enough to describe empirical observations (i.e. facts). You need to identify the theories (e.g. the explanation mechanism) that tentatively explain the empirical observations above. The theory, in this case, can be certain social class theory, or a social theory related to religious influence. With the theories so identified that have wider applicability, you could then evaluate these theories in your literature review and suggest why you think these chosen theories are relevant and useful for you to inform your research design and, subsequently, analyze your dissertation data to be gathered.