Why does Naval emphasize that "reputation is an invisible asset"?

Sure, here is the translation adhering to your requirements:

Answer: Okay, that's an interesting question. Let me try to explain it in plain terms.

Why does Naval put so much emphasis on this "reputation" thing?

Imagine you live in a small village.

Zhang San: This guy is honest and reliable. He always returns borrowed items on time. If he promises to help a neighbor fix a roof, he shows up without fail, rain or shine.
Li Si: This guy is a bit slippery. He always drags his feet when repaying debts; most promises he makes are broken. He also likes taking small advantages.

Now, a good money-making opportunity arises in the village, say, forming a partnership to sell local goods in the city. Who would you look for to partner with?

The answer is obvious: Zhang San.

In this example, Zhang San's "reliability" is his reputation. Can you see or touch this reputation? No. Is it written on Zhang San's forehead? No. But everyone in the village has a mental scale, and they all know Zhang San is trustworthy.

This is what Naval calls an "invisible asset".

Why is it considered an "asset"?

Simply put, an asset is something that brings you benefits and can help you "make money." A house is an asset – you can live in it or rent it out. Stocks are assets – they can pay dividends or appreciate in value.

Reputation works the same way; it brings tangible advantages:

Opportunities Come to You: As mentioned above, when good projects or jobs come up, the person everyone thinks of first is the one with a good reputation. You might not even need to compete fiercely; opportunities actively seek you out. This is the best kind of "passive income."
Low Cost of Trust: Collaborating with someone who has a solid reputation is reassuring. You don't need piles of complicated contracts or worry constantly that they'll run off. Both parties can focus energy on getting things done rather than guarding against each other. The time and effort saved this way are a huge wealth.
Provides Room for Error: Nobody's perfect. If a person known for a long-standing good reputation makes a small mistake, people tend to think, "Maybe it was a slip-up" or "There must be a special reason," and are often willing to give them a chance to explain or make amends. However, if someone with a poor reputation makes the exact same mistake, the reaction is, "See? I knew they weren't reliable!" A good reputation acts like your "capital reserve," helping you weather minor storms.
Inherent "Leverage Effect": Naval often talks about leverage. A good reputation is a powerful form of personal leverage. When your name signifies "reliability," "professionalism," or "high quality," one word from you carries more weight than ten words from someone else. You can price your products higher, and people will still buy because "When [Your Name] makes it, it must be premium." Your name becomes your brand, leveraging resources and value far exceeding what your individual efforts could achieve.

Why is it also emphasized as "invisible"?

This is the most unique, yet often overlooked, aspect of reputation.

It Cannot Be Quantified: How much money is in your bank account? Clear as day. But how much is your reputation worth? Impossible to calculate. It exists in people's minds and in societal consensus.
It Accumulates Painstakingly Slowly: Like our "Zhang San," a good name isn't built in a day. It accumulates through countless small acts – "returning things on time," "keeping promises" – little by little, building up gradually like a snowball. This process can take years, even decades.
It Can Be Destroyed Extremely Quickly: As the old saying goes, "Bad news travels fast." You might painstakingly build a good reputation for ten years, only for it to collapse overnight due to one serious breach of trust or one public lie. It's like a delicate porcelain piece: time-consuming and effortful to create, but shattered in an instant.

So, to summarize

Naval persistently emphasizes that "reputation is an invisible asset" to remind us:

In this increasingly interconnected modern world, don't just focus on visible money, power, and positions. Every action you take, and every word you say, is either a deposit into or a withdrawal from your "invisible bank account."

In the short term, this account might seem insignificant. But in the long run, it determines how far you can go, the quality of the opportunities you attract, and the caliber of people you connect with. Among all your assets, this is the one that most requires patient nurturing through Integrity and Time.

In essence, Naval encourages you to cherish your reputation and play the long-term game. Because ultimately, a good name will yield far greater returns than any act of opportunism dare ever could.