Overall, this is an excellent start to a compelling essay. Keep in mind that although the committee allows you to write up to five pages, three double-spaced pages is usually adequate. Feel free to add more detail, but make sure your text is concise and transparent. You might consider "writing" ideas and then "rewriting" them. Too often, authors put ideas onto the page, but do not render those ideas compellingly. Giving your sentences a bit of extra effort, and giving your experiences a bit of extra reflection, will result in a persuasive essay that compliments your accomplishments and character.
From the point of countries, politicians will perceive the ongoing situation as a wake-up call with regard to lower birth rates, more demands on houses, and more energy consumption. Firstly, more single households mean more single persons, and the population will shrink in the wake of falling number of married couples. Secondly, more houses are required to fulfill the need of individuals, which cause cities even more densely populated. London is a famous example; the number of houses has been stimulated by 48% over the past five years, and 80% of them are for singles. Finally, the consumption of electricity and gas will soar when more people choose to live on their own, and it will further pose a threat to our livelihood.