Taxis in Panama City must be among the cheapest in the world! I don't know how they make any profit, They are all yellow vehicles, privately owned. Ir seems that about evey third vehicle in the city is a taxi! The drivers, as a rule, speak only Spanish, Taxi fares within the ciry are generally $2 to $3. However, I advise settling on the price before you get into the taxi, so as to avoid an unpleasant experience, such as we had one time.
We had taken three taxi rides from our hotel to a particular address previously, and had paid $2 each time. So we didn't discuss the price in advance for the fourth ride, assuming it would be the same. When we arrived at our destination, my husband gave the driver $2. No, the driver said, it is $4. We refused to pay the extra money, and walked away with him yelling and threatening (I presume, since we don't speak Spanish) until we entered our building. Luckily, that was our last taxi ride in Panama, so there was no chance we would encounter that driver again.