“當他們淪落的時候，我們向高處走。”前美國第一夫人米歇爾·奧巴馬在美國充滿傳奇的城市費城召開的2016年民主黨大會上宣布。

在香港這裡，如今這句令人難忘的對比句提醒我的，不是曾經政治選舉的醜陋，更多的是這座城市引人注目的天際線之美麗。在亞洲，比以往更高的摩天大樓不斷出現，中國大大小小城市裡的開發商尤其接受了美國那種要建造高樓大廈的夢想。

誠然，當華盛頓新政府致力於重建美國的時候，前第一夫人說的話也同樣適用，只不過在美中兩國它有不同的、經濟上的語境。

美國總統唐納德·特朗普對摩天大樓肯定不陌生。紐約第五大道的特朗普大廈可以說是世界上最著名的所在之一。在建成世界上第一座摩天大樓的芝加哥市，2009年落成的特朗普國際酒店大廈是這座城市第二高已竣工建築物，也是美國第四高建築物。

很久以前，美國就把世界最高建築物的頭銜讓給了亞洲和中東。世界高層建築與都市人居學會（CTBUH）的數字顯示，世界已竣工的十座最高建築物當中，如今有七座在亞洲。這個總部位於芝加哥的非盈利組織創建於1969年，它維護的“摩天大樓中心”（The Skyscraper Center）是一個有關全球最高建築物的數據庫。

根據“摩天大樓中心”的數據，截至2017年3月，世界最高建築物是迪拜2717英尺的哈利法塔、2073英尺的上海中心大廈和沙特麥加1972英尺的麥加皇家鐘塔飯店。第四位是紐約1776英尺的世界貿易中心一號大廈，香港則擁有世界第八高建築物——環球貿易廣場。在東南亞，吉隆坡的石油雙塔、越南的京南河內地標大廈和曼谷近期完工的曼谷樓的高度都超過了1000英尺。

中國和亞洲的城市正以飛快的速度向四周和高處發展。這種建設熱潮很可能持續下去。世界銀行2015年發表的一份報告預計，未來幾十年將迎來城市的增長。儘管21世紀前十年，已有近2000萬人遷入亞洲的城市，但該地區的城市化程度可能還會越來越高。

但宜居的城市所需要的不僅僅是摩天大樓。民眾、街道生活和建築物底層的街坊們不應該被丟棄在新的發展陰影里。這一直是特別重要的問題，因為從香港到曼谷，亞洲的城市規劃者們正慢慢地趕走街頭小販、街邊裁縫和鞋匠、小推車和食品貨車。隨着城市越建越高，他們必須牢記宜居的三個重要基本點：社區、彈性和可持續性。

首先，社區必須放在城市發展的中心位置。城市規劃者必須考慮的不只是城市設計的影響以及新的交通效率或停車位建設，還要考慮不平等問題和人類的生活。

在追求房地產回報最大化的同時，開發商還必須引入公共的開放空間，營造社區歸屬感，改善街道生活，鼓勵社會化互動。理想的社區培育應當涵蓋各行各業、各種收入階層的人。

其次，城市建設必須有彈性。一個社會或城市擁有社會包容性，有強大的社區紐帶，那麼這座城市也會具有彈性。洛克菲勒基金會“100座彈性城市”倡議所定義的城市彈性，是指城市所擁有的生存、適應和增長能力，無論它經歷什麼樣的壓力或打擊。

除了摩天大樓，城市必須建立全方位的安全和法治、高效的公共衛生系統、包容性的住房與勞工政策、多樣化的交通運輸網絡，以及有效地提供緊急服務。在這裡，私人部門，包括保險和再保險公司，將與政府政策共同發揮必要的作用，為彈性建設創造有利的環境。

第三，城市發展方式應該是在環境上可持續的。隨着越來越多的人湧入城市，應對環境挑戰已經日漸成為一個城市問題。即使不是“智能城市”，對較智能城市的建設來說，在基建、能源和交通運輸等領域納入創新與技術也是至關重要的。同樣重要的是來自公共、私人和非盈利部門的貢獻。

衡量一座城市的成功有許多方式。在米爾肯學會（我是這家無黨派經濟智庫的創始亞洲研究員），我們的研究人員自1999年以來利用一套全面的、基於事實的標準，排列出了全美國200個大城市和201個小城市，作為年度表現最佳城市指數的組成部分。

這個基於經濟成果的指數主要側重於就業、工資和技術的增長。更多的主觀指標，如生活質量、生活成本，並沒有計入在內。

過去一年，技術仍然是高排名的推手，因為擅長創新城市的指數再次登頂，加州硅谷的聖何塞連續第二年排名第一。米爾肯學會一份類似的中國表現最佳城市排名，是基於官方公布的經濟、就業、工資增長、外國直接投資及其他數據，其結果是上海、貴陽和舟山排名領先。

當然，不是所有城市都擁有硅谷的城市或上海那種得天獨厚的資源，而即使這些地方也面臨越來越大的自然、社會、經濟挑戰，這是日益城市化的21世紀的一部分。

但在今天，在全球城市景觀變化的多樣性當中，有一點應該獲得一致認同。宜居、動感和充滿生機的城市比任何數量的摩天大樓——不管它們多麼雄偉多麼高——都更能證明國家的繁榮與政策的成功。隨着美國與中國的城市越建越高，其背後所堅守的東西才是最重要的。

“When they go low, we go high.” So declared former U.S. First Lady Michelle Obama at the 2016 Democratic Party convention in the storied American city of Philadelphia.

From here in Hong Kong, that memorable turn of phrase reminds me today less of the ugliness of past political campaigns, and more of the beauty of this city's striking skyline. In Asia, the march of ever-higher skyscrapers goes on, with developers in big and small cities in China in particular embracing that American dream to build high.

Indeed, those same words from the former First Lady have relevance – in a different, economic context in both the United States and China – as a new Administration in Washington focuses on rebuilding America.

U.S. President Donald J. Trump is certainly no stranger to skyscrapers. Trump Tower on Fifth Avenue in New York is arguably one of the most famous addresses in the world. In Chicago – site of the world's first skyscraper – the Trump International Hotel & Tower, completed in 2009, is the second tallest completed building in that city, and the fourth tallest in the United States.

The United States long ago ceded the title of world's tallest building to Asia and the Middle East. Seven of the top 10 tallest completed buildings in the world are now in Asia, according to the Council on Tall Buildings and Urban Habitat. This Chicago-headquartered not-for-profit organization founded in 1969 maintains The Skyscraper Center, a database on the world's tallest buildings.

As of March 2017, the world's tallest buildings are the Burj Khalifa in Dubai at 2717 feet, the Shanghai Tower in China at 2073 feet and the Makkah Royal Clock Tower in Mecca, Saudi Arabia, at 1972 feet, according to the Skyscraper Center. Coming in at number four is 1 World Trade Center in New York at 1776 feet. Hong Kong boasts the eighth tallest building – the International Commerce Center. In Southeast Asia, the tallest buildings are Kuala Lumpur's Petronas Twin Towers; the Keangnam Hanoi Landmark Tower, in Vietnam; and Bangkok's recently completed MahaNakhon tower – all at more than 1000 feet tall.

Cities in China and across Asia are growing outwards and upwards at breakneck speed. This construction boom is likely to continue, according to a report from the World Bank in 2015 that forecast decades of urban growth to come. Despite almost 200 million people already having moved to Asia's cities in the first decade of the 21st century, the region's ongoing urbanization is likely only to intensify.

Livable cities, however, need more than skyscrapers. The people, the street life, and the neighborhoods at the bottom of the buildings must not be lost in the shadows of new development. That remains a particularly critical point as city planners across Asia, from Hong Kong to Bangkok, slowly push out street vendors, street-side tailors and cobblers, push carts and food trucks.As cities build taller, they must keep three key benchmarks for livability in mind – community, resilience and sustainability.

First, communities must be put at the heart of urban development. Urban planners must consider not only the impact of a city's design and new construction on traffic efficiency or parking spaces, but also on inequality and on human lives.

Amidst the rush to maximize real estate returns, developers must also incorporate public, open spaces to build a sense of community, cultivate street life and encourage social interaction.And that fostering of community should ideally include people from all walks of life and income levels.

Second, cities must build in resilience.A society or city that is socially inclusive and with strong community bonds leads to a city that is also resilient. An initiative of the Rockefeller Foundation, 100 Resilient Cities, defines urban resilience as the capacity to survive, adapt and grow no matter the stresses or shocks they experience.

Beyond skyscrapers, cities must build in comprehensive security and rule of law, effective public health systems, inclusive housing and labor policies, and diverse transport networks, as well as effective delivery of emergency services. Here, the private sector, including insurance and reinsurance companies, will play a necessary role along with government policies to encourage an enabling environment for resilience.

And third, cities need to grow in an environmentally sustainable manner.With more and more people moving into cities, tackling environmental challenges is already increasingly an urban issue. Incorporating innovations and technologies in areas such as infrastructure, energy and transport will be essential to building smarter if not “smart cities.” Here again, the contributions and coming together of public, private and not-for-profit sectors will be important.

There are many ways to measure a city's success. At the Milken Institute, where I serve as that non-partisan economic think tank's inaugural Asia Fellow, our researchers since 1999 have used a comprehensive, fact-based set of criteria to rank 200 large and 201 small metros across the United States as part of an annual Best-Performing Cities index.

The economic outcomes-based index heavily weights growth in employment, wages and technology. More subjective metrics such as quality-of-life and cost-of-living are not included.

This past year, tech still drove the top rankings as cities that exceled in innovation again topped the index, with San Jose, California, in Silicon Valley, claiming the No. 1 spot for the second year in a row. A similar Milken Institute Best Performing Cities China list based on official Chinese economic, jobs, wage growth, foreign direct investment and other data singled out Shanghai, Guiyang, and Zhoushan as top performers.

Certainly, not all cities are blessed with the resources that Silicon Valley's urban areas or Shanghai have as they too face the growing physical, social and economic challenges that are a part of an increasingly urbanized 21st century.

But today, amidst the diversity of the world's changing urban landscapes, on one point there should be agreement.Livable, dynamic and vibrant cities are greater testament to a country's prosperity and policy successes than any number of skyscrapers, no matter how big or how tall. As cities in America and China build higher, it is what is sustained below that will matter most.