Writing a cause-effect paragraph is not that hard: you can either start by a cause and then explaining the effects; or the other way around, start with the effect and explain the causes.
Let’s examine these two different types of paragraphs one by one:
1) Starting by a CAUSE:
Let’s say you start with rising fertility rate in rural villages. That’s a CAUSE.
What would be the effect(s)? Rising population, falling living standards of agricultural productivity remains the same, and thus eventually a migration to cities.
Here as you can see the crucial component is the ASSUMPTION that agricultural productivity will remain the same. This is important because if the productivity goes up it can support a growing population and thus there won’t be any urban migration.
You start by a TOPIC SENTENCE which describes the CAUSE. Then you continue by listing the EFFECTS. Important thing is to make clear what your ASSUMPTIONS are in your line of reasoning.
Example:
“Fertility rate has risen 7% in Western XYZ between 1990-2010 [THE CAUSE]. One effect of this would be increased pressure on food resources, if the agricultural productivity remains the same [THE ASSUMPTION]. A second and related effect would be dropping standard of living in Western XYZ. We should expect this to lead to an eventual migration to the cities in the region like La Capital [THE CAUSE].”
2) Starting by an EFFECT:
You start by a TOPIC SENTENCE which describes the EFFECT. Then you continue by listing the CAUSES. Important thing is to make clear what your ASSUMPTIONS are in your line of reasoning.
Example:
“Those with a college degree are shown to earn a million dollars more over a lifetime than those who do not go to college at all [THE EFFECT]. One reason why this is so is the higher paying jobs available to college graduates [CAUSE 1]. Another reason is college graduates are more comfortable with high-technology and that helps them start hi-profit businesses [CAUSE 2]. Of course, we are here assuming that the two group (college and non-college) start their adult lives more or less from similar socioeconomic backgrounds.”
As you can see, even though there is a structure to the way a cause-paragraph is written [TOPIC SENTENCE first, followed by supporting effect or cause sentences], there are no standard phrases or keywords that you need to use while writing them. As a writer you should use your creativity and come up with the correct style to stitch together the cause and effect elements together as shown in the above examples.