The task of potty training can be a challenging phase in a child's development, often leaving parents feeling overwhelmed and unsure about the best approach. It is centered on two main objectives: achieving physiological readiness and psychological willingness in the child. This is where the role of a potty training consultant becomes significant. These professionals act as a torchbearer, guiding parents through this rather arduous journey, providing strategies and customized plans that best suit the child's pace and temperament.

Akin to hiring any other professional, the hiring of a potty training consultant too involves some due diligence.

Firstly, let's delve deeper into the 'raison d'être' of potty training consultants. The term 'consultant' typically implies an expert in a particular field who provides professional advice. Extrapolating that definition, a potty training consultant is an expert in child behavior and developmental milestones, particularly related to toilet training. Anecdotal evidence and empirical studies suggest that professional help in potty training can significantly reduce the training period and potential setbacks, making the process smoother for both child and parent.

Let's now turn to the parameters you should consider when hiring a potty training consultant.

First, their professional qualifications and experience. As potty training is closely related to child psychology and development, a professional background in these fields adds credence. Similarly, practical experience is invaluable. A potty training consultant with several years of experience is likely to have dealt with a variety of cases, enabling them to handle diverse and challenging situations effectively.

Next, methodology and philosophy. There are various potty training techniques, from the Brazelton method, which advocates for waiting until the child shows readiness, to the Azrin and Foxx’s rapid method, which involves a more intensive training over a shorter period. Each has its own merits and demerits. Some children respond better to a relaxed approach, while others need a more structured regime. The consultant’s philosophy should align with your parenting style and the child's temperament.

Moreover, consider their reputation and references. Testimonials from previous clients are a valuable source of information. They can provide insights into the consultant's effectiveness, reliability, and interaction style. It's also essential to ensure the professional’s legitimacy, as the field is unregulated and lacks universally accepted standards.

Lastly, consider the cost. Potty training consultancy is a niche service and can be expensive. However, the benefits of a smoother, less stressful potty training experience often outweigh the financial expenditure.

To illustrate the importance of hiring the right consultant, consider the economic concept of 'opportunity cost'. The time and energy parents invest in stressful, ineffective potty training methods could be spent on other beneficial activities. Therefore, hiring a consultant could lead to an overall gain, even if there's an upfront cost.

In conclusion, while potty training is a natural developmental milestone, the path to it can be fraught with challenges. A potty training consultant can make the journey smoother and less stressful, provided you choose the right one. By considering their qualifications, experience, methodology, reputation, and cost, you can make an informed decision that best suits your child's needs and your family situation. Remember, the goal is not just to train your child to use the potty, but to make the process a positive and empowering experience for them.