stiggy

The guy with the "give a set amount" is on the right track.  You're not dealing with some pervasive Thai behavior here, as has been erroneously stated, you're dealing with lower and working class Thai behavior and with transient unskilled labor bhehavior.  There are no HiSo, internationally educated Thai men and women with names ending in Na Ayuttayah slumming it in Phangan and Samui for the Summer.  It simply does not happen.  You might have some overlap with middle class (maybe even upper middle class), but that's mostly going to come out of places like Mahidol and beeline straight for the 5 stars.  I'll grant that the unannounced departures and things of that nature are something you do not experience even in working class places in developed Western countries, but you also don't find it here among the internationally educated crowd (sadly, you do too often among the locally educated university crowd).

So, what you're dealing with is pretty similar to what goes on on resort islands (and other similar locales) throughout the world.  A bunch overworked, low-cost labor that mostly wants to have a good time and relax.  Complex bonus structures and incentive programs can work with the kind of people who go for such things (sales staff, traders, brokers, etc), but you've got essentially uneducated hospitaly workers here.  The truth about worker motivations is often fairly misunderstood.  Most people in this world don't want a chance to earn a ton more money via Kafkaesque scheme, they want enough to get by and enjoy their lives and spend as much time not-working as possible.  I ran across this a few years ago by way of trying to explain why complex incentive structures don't work to a typical consultant/finance world entrepreneur here who burns through staff like a hot knife through butter (foreign and domestic):



It's not a treatise on the topic, but it's short and summary and if you're open to modifying your opinions on human behavior (and especially as a gauchiste you'll probably find that this rings true.  Just sit through the first candle problem thing and it becomes relevant.  This kind of thing becomes even more true the lower you get on the socioeconomic ladder in countries where there's no trust in institutions and employers (for good reason).