Questions about example sentences with, and the definition and usage of "Birthdate"

A: Birthday or date of birth

A: × The decreasing birthdate in Japan is a major problem and it has caused serious concerns on our economy, tax and society.
✓ The decreasing birth rate in Japan is a major problem and it has caused serious concerns to our economy, tax and society.

× There are three reasons to support my opinion.
✓ There are three reasons that support my opinion.

× First, our economy is supported by workforce, however, the number of workforce is decreasing due to the low birth rate.
✓ First, our economy is supported by workforce. However, this workforce is decreasing due to the low birth rate.

× The fact that it is difficult for many companies to hire new employees who just graduated from their university recently shows that the decreasing birth rate has effected.
✓ The fact that recently it's difficult for many companies to hire new employees who just graduated from university shows that the decreasing birth rate has greatly affected them too.

× Second, according to the decreasing workforce, a serious tax concern has occurred.
✓ Second, due to the decreasing workforce, a serious tax concern has occurred.

× Recent decades our senior generation rate has been increasing compared with other generations rate, which means that a few workforce supports a big amount of the senior’s pension.
✓ In recent decades, our senior generation's taxes have been getting more expensive compared to other generations' taxes, which means that a little workforce supports a big amount of the senior’s pension.

I'm not too sure about the last sentence. What did you want to say?

A: × The decreasing birthdate in Japan is a major problem and it has caused serious concerns on our economy, tax and society.
✓ The decreasing birthdate in Japan is a major problem and it has created serious problems in our economy and society.

× First, our economy is supported by workforce, however, the number of workforce is decreasing due to the low birth rate.
✓ First, our economy is supported by the workforce, however, the size of the workforce is decreasing due to the low birth rate.

× The fact that it is difficult for many companies to hire new employees who just graduated from their university recently shows that the decreasing birth rate has effected.
✓ The fact that it is difficult for many companies to hire new employees who just graduated from university recently shows that the decreasing birth rate has an effect.

× Second, according to the decreasing workforce, a serious tax concern has occurred.
✓ Second, due to the shrinking workforce, tax revenue have decreased

× Recent decades our senior generation rate has been increasing compared with other generations rate, which means that a few workforce supports a big amount of the senior’s pension.
✓ In the recent decades the proportion of pensioners have increased compared to other age groups, which means that a smaller workforce supports a large amount of the senior’s pension.

-effect is not a verb

-tax is a part of economy

-workforce is not a number, it is a noun. So it shrinks and grows/expands and is big or small.

-I know what you mean by a “a serious tax concern has occured”, it’s correct but in english, we don’t say it like that. Instead, you can use “… created a serious tax concern”

If you have any other questions please ask