Background:
The primary method for getting around Maumere is either by overcrowded mini-bus called a 'Bemoh,' or on the back of motorbike taxi called an 'Ojek.' Anyone with a motorbike can be an Ojek driver (there isn't any specific designation), and all bikes travel at the same relative speed (frighteningly fast).
Revenue:
We routinely traveled the 25 minute ride between downtown Maumere and the Sao Resort where our boat was anchored for 10,000 IDR. Some rides were longer (about 40 minutes to the museum, or 60 minutes to our friend Nofi's home), yet we paid the same rate of 10,000 IDR for each of those rides. Throughout Indonesia, we have often paid higher prices than the locals (on account of being obvious tourists). Our 'Tourist markup' has ranged from 33 to 200%. 10,000 IDR for a 25 minute ride is thus an upper-bound.
On one morning ride into town, I counted empty ojeks out of a 10 bike sample every two minutes. I considered those carrying people, rice, baked goods, water bottles, or other cargo as 'occupied.' On this particular ride, I found an average of 4.2 Ojeks out of ten to be 'available.' Given this assumption of 42% of the driver's time spent looking for rides, a driver could fit approximately 11 rides into an 8 hour workday. Since many ojeks do not roam, but rather park and wait in central locations (such as the market), there are likely more empty bikes in the town at any one time than roaming the streets. Thus this estimate is similarly an upper-bound.
Using this information, the upper-bound estimate of a driver's expected daily revenue is 110,000 IDR.
Costs:
The following information was collected from discussions with staff at the Sao Resort, a taxi driver, and two different ojek drivers. The bikes used as ojek's are simple 50cc gasoline powered motorbikes. A bike might last 10 years and a new Honda or Yamaha costs around 50,000,000 IDR. A driver might put four liters of gasoline in the bike to cover a full day's worth of driving, and the maintenance costs of a bike are low (I am assuming 15% of the bike's value over its lifetime).
Using a ten-year time horizon with no salvage value, a 15% lifetime maintenance cost, and a 5% discount rate, the present value daily cost of owning a motorbike is 20,401 IDR. The cost of a day's worth of driving (four liters of gasoline at 4,500 IDR/liter) is 18,000 IDR.
It is unclear whether these costs represent a lower or upper bound. A different discount rate (due to fewer alternative investment options, uncertainty in the stability of the rupiah, or a high probability of accidents), lower maintenance costs, a higher salvage value, or alternative and cheaper brands of new bikes can skew this estimate in either direction. However, all of the assumptions made are based upon the best information available at the time.
The expected daily cost of operating an ojek is thus 38,401 IDR.
Results:
Using the above estimates for the revenue and cost over an 8 hour workday, an ojek driver's expected daily take-home income is 71,599 IDR. This equates to 8,950 IDR per hour. Using 8,817 IDR as the 1 USD equivalent, the expected value estimate for the hourly wage of an ojek driver is 1.02 USD per hour.
In comparison with the other informal low-skill jobs visible in Maumere (fisherman, market vendor, restaurant operator, bemoh driver), ojek drivers seemed to be on average wealthier and better dressed. Most had cellular phones and fashionable helmets. Becoming an ojek driver requires a significant up-front investment. Shop-owners, taxi drivers, bank employees, and government officials, in turn were clearly wealthier than ojek drivers. Within the context of the full labor marker, the ojek driver wage rate appears to be higher than most informal low-skill jobs, however certainly lower than the formal skilled labor market.
Please keep in mind that this is a back-of-the-envelope calculation in its truest form (I even did some of the math on the back of an envelope).