Sometimes during the summer vacation my ten year old son needs a little extra incentive to learn so I tell him that I will pay him two dollars for every hour that he learns. Am I obligated to pay him the same day like a worker?
Before we address your question we should mention a few points by way of introduction. The Gemoro (Succa 46B) writes that one who tells a child that he will give him something must honor his word because otherwise the child will learn to lie. Moreover, most poskim maintain that one who violates this Gemoro is even considered a mechusar amono-a non-trustworthy individual, which has halachic consequences. (See our sefer Mishpetei Yosher pages 356-7 and 344-351 where we discuss this issue at length.)
Furthermore, one who tells a child that he will pay him to perform a task is not allowed to refuse to pay him since if he does so he will violate Torah prohibitions including theft and oshek sechar sochir. The latter is a specific Torah prohibition that one violates if he fails to pay his worker and one certainly violates a positive and negative Torah commandment when he refuses to pay an adult worker. The Chafetz Chaim points this out in Ahavas Chesed (9, footnote 16) and proves that a child must also be paid on time and one who fails to pay a child on time violates the same Torah commandments as one who does not pay an adult on time.
In one sense, the law concerning a child is even stricter. When an adult doesn’t request his salary, the employer is not enjoined to pay the employee on time, whereas by a child he must still pay him. The reason is that with the adult worker we interpret his failure to request payment as indicating that he is waiving his right to immediate payment whereas by a child we attribute his failure to request payment to bashfulness. Therefore, the employer must pay on time even if the child never requests payment.
Based on the above, your question has nothing to do with the fact that your son is a minor, but only with the nature of the task. The law that one must pay on time is specific to employees. If one owes a debt or must pay for damages he caused, he must pay but there is no mitzvah requirement to pay immediately as there is for a debt to an employee. Therefore, we must investigate whether you are indeed employing your son to do a job, or perhaps even though you obligated yourself to pay and you must pay, he is not halachically your employee.
The reason he may not be your employee is, as you say, you offered him money as an incentive. The question thus is a specific instance of a more general question: does one who offers someone an incentive to perform a task have to pay immediately? There is no general rule stating whether one who performed a task because he was offered an incentive by someone is considered by the halachah as that person’s employee. Furthermore, there is no Gemara that deals directly with this issue. What is found is only poskim who discuss whether specific types of incentives create an employer-employee relationship.
The poskim discuss two incentives. One is where a person offered someone an incentive to perform an action he should have performed even without the incentive. The typical situation is where someone was not keen on performing a mitzvah that he was obligated to perform and only performed the mitzvah after being offered an incentive. The question the poskim have in this case is whether in order to attain the status of an employer, the employer must be the cause for the employee to perform the task which is obviously not the case where there was already a mitzvah obligation.
The second situation where such a question is discussed is where a person offered someone money to do something for himself. The reason the worker may not have the status of an employee is because the one who offered the incentive did not expect to receive anything in return for his money. We find in the Gemara (BM 118A) that if A asks B to do something for C, B is an employee of A. That is because when he does something for C it has the same status as if he worked for A. (This is derived from the halachah that cosigner A becomes obligated to pay B, when B lends money to C because A told him to do so.) However, we do not find that if A asked B to do something for B, then B is an employee of A.
The first type of incentive is the subject of a dispute between the Ketsos (81, 4) and the Tumim (81, 6) against the Nesivos (81, 2). A person offered money to his son-in-law to teach his own son Torah. The Ketsos and Tumim claim that the father-in-law effectively hired the son-in-law to teach his own son. The Nesivos, who was a contemporary of the Ketsos, disagreed. In the first edition of the Nesivos, he argued that the son-in-law cannot be classified as an employee because the son-in-law was already obligated by the Torah to teach his son Torah. (The father did not send him to yeshiva or hire a private tutor to teach him.) He agreed that the father-in-law can obligate himself to pay, but he says that is just like any monetary obligation that a person can accept upon himself and it is not governed by the laws of employees.
The Ketsos (in the Meshoveiv Nesivos) cites the Maharam of Rottenberg who clearly disagrees with the Nesivos, as proof that the Nesivos is incorrect. Additionally, others cite the Ramban (Yevamos 106A) who writes that a doctor has the status of an employee when he works for a fee even though he is obligated to heal his fellow Jew, as disagreeing with the Nesivos. (The Gemoro (Nedarim 38B) derives from the mitzvah of hashovas aveido that a doctor has a mitzvah to heal his fellow Jew.) Furthermore, Rashi and many other Rishonim (Yevamos 106A) write that one who offers money to a man to perform chalitzo with the latter’s sister-in-law is considered as having hired the man to perform chalitzo even though that is what he was supposed to do.
In the second edition of his sefer, the Nesivos responded to the Ketsos’ criticism and admits that the Maharam disagrees with him. He cites the Shach however, who maintains that when a person offers money to someone to do what he is supposed to do anyway and does not derive any benefit from what he paid for, then the worker is not an employee. This is somewhat different from what he first wrote. However, this applies to your situation since you have no direct benefit from your son’s learning.
In summary, the Ketsos and Tumim maintain that when one worked because he was offered an incentive, he is classified as an employee even if the employee was paid to do what he was supposed to do anyway and even if the one who paid did not derive any benefit from what he paid for. The Nesivos seems to agree that where the one who paid gained from the action of the worker, even if the worker was just doing what he was supposed to do, the worker is an employee. However, if the worker was doing what he was supposed to do and also the one who paid did not gain from what he paid for, the Nesivos maintains that the Shach would not classify the worker as an employee. He agrees that the Maharam would classify him as an employee.
The Shimru Mishpot (1, 81) discusses a case of an incentive that was offered to do something one should not do. One boy offered another boy money if he would jump from one porch to another, a dangerous feat. After the boy succeeded, he asked for his payment. The other boy refused. The boy who jumped claimed he was an employee and deserved payment.
The Shimru Mishpot agreed that the boy did not have to pay, citing a Rama (129, 22) who rules that one does not have to pay someone who agreed to serve as a cosigner for a fee since people normally (then) did not charge to serve as cosigners. His argument is that people do not charge to jump porches. His comparison is debatable because in the case of the Rama people served as cosigners without asking for money, but people do not jump for free. They simply don’t do dangerous things. Therefore, since the boy only agreed to jump because he was offered money one can argue that he is an employee. A similar argument is given by the Maharit (1, 45)
Returning to your question if you have to pay immediately, there is a second issue that needs clarification. The Shoeil Umeishiv (2, 3, 42) was asked about another case of an incentive. Someone wanted to help a poor tailor. He gave the tailor material and told the tailor he should sew himself a garment and he would pay him for the work. The Shoeil Umeishiv ruled that if the benefactor does not pay on time he does not violate bal tolin even though the tailor was his worker. He bases his position on the words of the pasuk (Vayikro 19, 13) that is the source of the prohibition to pay a worker late. He interprets this to mean that the Torah only forbids paying a worker late if the one who must pay already received the fruits of the labor. However, here since the goods (the finished garment – peulas sochir) remained with the tailor, there is no Torah prohibition to pay late. (As an aside, we should note that obviously the Shoeil Umeishiv maintains that the second type of incentive creates an employer-employee relationship.)
In your situation too, since you are paying your son to do something for himself he would maintain that you would not violate the prohibition of bal tolin, even according to the Ketsos and Tumim. However, this chiddush of the Shoeil Umeishiv is very difficult because the Gemara (BM 112) and the Toras Kohanim and the Targum all interpret the words peulas sochir to mean the salary, and not the goods as the Shoeil Umeishiv interprets. Therefore, it is very difficult to rely on the Shoeil Umeishiv especially when dealing with a Torah prohibition.
In conclusion: You should pay your son on time and have in mind to fulfill the Torah mitzvah to pay your workers on time. Even though according to the Nesivos and the Shoeil Umeishiv you will not violate a prohibition if you don’t pay on time, but the Ketsos and Tumim disagree with the Nesivos, and the Shoeil Umeishiv is very difficult and you are dealing with a Torah prohibition.
We would add that since you are trying to educate your son, this will enhance his education since he will learn from his father’s actions the importance of paying employees on time and nothing educates better than personal example.